On

/ɔn/ adj, adv, name, noun, prep, verb, slang

adj, adv, name, noun, prep, verb, slang ·Top 500 ·Elementary level

Meaning at a glance

  • Primary sense: In the Japanese language, a pronunciation, or reading, of a kanji character that was originally based on the character's pronunciation in Chinese, contrasted with kun.
  • Grammar: on is listed as adj, adv, name, noun, prep, verb, slang.
  • Nearest alternatives: about, about, above, above water.
  • Useful contrasts: off, errors in counting, in head calculation.
  • Usage evidence: Tomorrow, he will land on the moon.

How to use "on"

  1. Start with the primary definition, then check the part of speech before placing the word in a sentence.
  2. Compare nearby synonyms to make sure "on" carries the exact meaning, tone, and strength you need.
  3. Use the example sentence as a context check. If your sentence uses the word differently, confirm that the grammar still fits.

Meaning check

  • Does the word fit the sentence's grammar?
  • Does it match the intended tone rather than only the dictionary definition?
  • Would a simpler synonym be clearer for the reader?
  • Is there enough surrounding context to prevent ambiguity?

Source and review context

This entry combines structured lexical data with WordToolSet review checks. Definitions, examples, synonyms, and usage notes may come from different source tables, so the page is designed to show evidence from more than one angle before you rely on "on" in a final draft.

If a word has several senses, prefer the sense that matches your sentence's grammar and surrounding context. A correct definition can still be the wrong choice when the sentence needs a different register, emphasis, or level of specificity.

Before you rely on this definition

Read the first definition as a starting point, then check the example, synonyms, and part of speech before treating "on" as the right word for your sentence.

If your draft is formal, technical, persuasive, or sensitive, compare "on" with a nearby alternative so the final choice matches both meaning and reader expectation.

Compare nearby meanings

  • Use synonyms when you need a softer, stronger, simpler, or more specific word.
  • Use antonyms to check the boundary of the meaning and avoid accidental contrast.
  • Use the example sentence to confirm the word behaves naturally in context.
  • Keep the original wording when a replacement adds complexity without improving precision.

Definition decision workflow

1. Identify the role

Check whether "on" is acting as adj, adv, name, noun, prep, verb, slang in your sentence. A definition is only useful when the grammar matches the way the word is being used.

2. Test the nearest option

Compare it with "about" and other nearby choices to see whether the sentence needs a softer, stronger, or more familiar word.

3. Confirm with context

Use the example sentence below as an evidence check, then read your own sentence out loud to catch tone or rhythm problems.

Review note: Definition pages are checked for source coverage, sentence evidence, synonym support, and editorial insight before they are treated as approval-ready pages. If the evidence is too thin, the page remains available to users but is kept out of the approval-facing indexed inventory.

Final meaning check

Before publishing a sentence with "on", ask whether the word helps the reader understand the idea faster. A precise word should reduce confusion, not simply make the sentence look more polished.

When the definition, synonym evidence, and example context point in the same direction, the word is usually a safer choice. When they conflict, revise the sentence or choose a clearer alternative.

Definitions

Noun
  1. 1
    In the Japanese language, a pronunciation, or reading, of a kanji character that was originally based on the character's pronunciation in Chinese, contrasted with kun.

    "Most kanji have two kinds of reading, called "on" and "kun"."

Verb
  1. 1
    To switch on. Malaysia, Nigeria, Philippines, Singapore, colloquial, transitive

    "Can you on the light?"

Adjective
  1. 1
    In the state of being active, functioning or operating. not-comparable

    "All the lights are on, so they must be home."

  2. 2
    Happening; taking place; being or due to be put into action. not-comparable

    "We had to ration our food because there was a war on."

  3. 3
    Happening; taking place; being or due to be put into action.; Of a person, used to express agreement to or acceptance of a proposal or challenge made by that person; most commonly with subject "you" (see you're on). informal, not-comparable

    ""Five bucks says the Cavs win tonight." ―"You're on!""

  4. 4
    Fitted; covering or being worn. not-comparable

    "Your feet will soon warm up once your socks are on."

  5. 5
    Of a stated part of something, oriented towards the viewer or other specified direction. not-comparable, postpositional

    "The photograph shows the UFO side on."

Show 9 more definitions
  1. 6
    Acceptable, appropriate. UK, informal, not-comparable

    "It's not fair to do that – it's just not on."

  2. 7
    Possible; capable of being successfully carried out. not-comparable

    "Climbing up that steep ridge isn't on. We'll have to find another route."

  3. 8
    Available; remaining. not-comparable

    "Smith is 25 points ahead with only 23 on."

  4. 9
    Having reached a base as a runner and being positioned there, awaiting further action from a subsequent batter. informal, not-comparable

    "With one out and no men on, Tristen Carranza belted a ball to the opposite field for a solo home run to put the NM State deficit at just 2-1."

  5. 10
    Within the half of the field on the same side as the batsman's legs; the left side for a right-handed batsman. not-comparable

    "The captain moved two fielders to the on side."

  6. 11
    Of a ball, being the next in sequence to be potted, according to the rules of the game. not-comparable, postpositional

    "If the player fails to hit the ball on, it's a foul."

  7. 12
    Acting in character. not-comparable
  8. 13
    Performative or funny in a wearying manner. informal, not-comparable

    "He always has to be on, it's so exhausting."

  9. 14
    Menstruating. euphemistic, not-comparable

    "It still gets in the way of her doing things like swimming, and she avoids sleepovers when she's "on"."

Adjective
  1. 1
    in operation or operational wordnet
  2. 2
    (of events) planned or scheduled wordnet
Adverb
  1. 1
    To an operating state. not-comparable

    "turn the television on"

  2. 2
    So as to cover or be fitted. not-comparable

    "The lid wasn't screwed on properly."

  3. 3
    Along, forwards (continuing an action), onwards. not-comparable

    "The policeman moved the tramp on."

  4. 4
    In continuation, at length. not-comparable

    "and so on"

  5. 5
    Later. not-comparable

    "Ten years on, nothing had changed in the village."

Show 2 more definitions
  1. 6
    Of betting odds, denoting a better-than-even chance. See also odds-on. not-comparable

    "That horse is twenty-to-one on, so you need to stake twenty pounds just to win one pound."

  2. 7
    Of a ball, into a pottable position. not-comparable

    "The black was previously unavailable, but in potting that red, he's now pushed the black on."

Adverb
  1. 1
    with a forward motion wordnet
  2. 2
    indicates continuity or persistence or concentration wordnet
  3. 3
    in a state required for something to function or be effective wordnet
Preposition
  1. 1
    Indicating position or location.; Positioned at the upper surface of, touching from above.

    "A vase of flowers stood on the table."

  2. 2
    Without. Scotland, UK, dialectal
  3. 3
    Indicating position or location.; Positioned at or resting against the outer surface of; attached to.

    "He had a scar on the side of his face."

  4. 4
    Indicating position or location.; Covering.

    "He wore old shoes on his feet."

  5. 5
    Indicating position or location.; At or in (a geographical location or position).

    "The lighthouse that you can see is on the mainland."

Show 43 more definitions
  1. 6
    Indicating position or location.; At (a relative spatial position).

    "We live on the edge of the city."

  2. 7
    Indicating position or location.; Near; adjacent to; alongside; just off.

    "The fleet is on the American coast."

  3. 8
    Indicating position or location.; Aboard (a mode of transport, especially public transport, or transport that one sits astride or uses while standing).

    "on a bus, on a train, on a plane, on a ferry, on a yacht"

  4. 9
    Indicating position or location.; In the direction of (some part of one's vessel), to within 45 degrees.

    "A ship was sighted on the port quarter."

  5. 10
    Expressing figurative placement, burden, or attachment.

    "All of the responsibility is on him."

  6. 11
    Denoting physical contact or interaction with an object, such as impact or application of force.; With verbs describing an action of pushing, pulling, pressing, etc., designates the thing to which force is applied.

    "tug on the rope; push hard on the door"

  7. 12
    Denoting physical contact or interaction with an object, such as impact or application of force.; With verbs describing an action of hitting, rubbing, scratching, binding against, etc., designates the thing impacted or contacted.

    "I stubbed my toe on an old tree stump."

  8. 13
    Denoting physical contact or interaction with an object, such as impact or application of force.; Denoting performance or action by contact with the surface, upper part, or outside of anything; hence, by means of; with.

    "to play on a violin or piano"

  9. 14
    Supported by (the specified part of itself).

    "A table can't stand on two legs."

  10. 15
    At (a certain value or level). UK

    "The Tories are on twenty-five percent in this constituency."

  11. 16
    At (a certain position within a sequence).

    "I'm on question four."

  12. 17
    At or during the date or day of.

    "Born on the 4th of July."

  13. 18
    At (a given time after the start of something). UK, especially

    "Smith scored again on twelve minutes, doubling Mudchester Rovers' lead."

  14. 19
    At (an instant or cusp).

    "on the stroke of midnight; on the "B" of "Bang!""

  15. 20
    Dealing with the subject of; about; concerning.

    "I was reading a book on history."

  16. 21
    Indicating a means or medium.

    "I saw it on television."

  17. 22
    Indicating the target of, or thing affected by, an event or action.

    "They planned an attack on London."

  18. 23
    In the possession of. informal

    "I haven't got any money on me."

  19. 24
    Because of; due to; upon the basis of (something not yet confirmed as true).

    "to arrest someone on suspicion of bribery"

  20. 25
    At the time of (and often because of).

    "On Jack's entry, William got up to leave."

  21. 26
    Arrived or coming into the presence of.

    "I need to get my planting done, as the season will soon be on us."

  22. 27
    Paid for by.

    "The drinks are on me tonight, boys."

  23. 28
    Toward; for; indicating the object of an emotion.

    "Have pity or compassion on him."

  24. 29
    Indicating the person experiencing an emotion, cold, thirst, hunger, etc. Ireland, especially

    "I had a terrible thirst on me."

  25. 30
    Indicating a means of subsistence or sustenance.

    "They lived on ten dollars a week."

  26. 31
    Engaged in or occupied with (an action or activity).

    "He's on his lunch break."

  27. 32
    Regularly taking (a drug).

    "You've been on these antidepressants far too long."

  28. 33
    Under the influence of (a drug, or something that is causing drug-like effects).

    "He's acting crazy because he's on crack right now."

  29. 34
    In addition to; besides; indicating multiplication or succession in a series.

    "heaps on heaps of food"

  30. 35
    Indicating dependence or reliance.

    "I depended on them for assistance."

  31. 36
    Serving as a member of.

    "He is on the jury; I am on the committee."

  32. 37
    By virtue of; with the pledge of.

    "He affirmed or promised on his word, or on his honour."

  33. 38
    By virtue of; with the pledge of.; Ellipsis of I swear on: on my life, on God, on everything, etc. abbreviation, alt-of, ellipsis, informal
  34. 39
    To the account or detriment of; denoting imprecation or invocation, or coming to, falling, or resting upon.

    "On us be all the blame."

  35. 40
    Against; in opposition to.

    "The fight was three on one, and he never stood a chance."

  36. 41
    According to, from the standpoint of; expressing what must follow, whether accepted or not, if a given premise or system is assumed true.

    "On naturalism, it is therefore difficult to find a ground for ultimate moral hope."

  37. 42
    In a position of being able to pot (a given ball).

    "All the way around the table, off four cushions, and ... and he's on the black!"

  38. 43
    Having as identical domain and codomain.

    "a function on #92;mathbb#123;R#125;"

  39. 44
    Having Vⁿ as domain and V as codomain, for the specified set V and some integer n.

    "an operator on #92;mathbb#123;Z#125;"

  40. 45
    Generated by.

    "the free group on four letters"

  41. 46
    Divided by. uncommon

    "Twenty on three."

  42. 47
    Of. dialectal, obsolete, regional

    "I never seen 'im, and that's the truth on it."

  43. 48
    At the peril of, or for the safety of. obsolete

    "Hence on thy life: the captive maid is mine; / Whom not for price or pray'rs I will reſign: [...]"

Proper Noun
  1. 1
    Initialism of Old Norse. abbreviation, alt-of, initialism
  2. 2
    Synonym of Heliopolis (“ancient Egyptian city”).
  3. 3
    Abbreviation of Ontario: a province of Canada. abbreviation, alt-of

Synonyms

All synonyms
aboutaboutaboveabove wateraccidentalaccompanying

Antonyms

offerrors in countingin head calculationout

Example

"Tomorrow, he will land on the moon."

Common questions

What does "on" mean?

In the Japanese language, a pronunciation, or reading, of a kanji character that was originally based on the character's pronunciation in Chinese, contrasted with kun.

What is a synonym for "on"?

Common synonyms include: about, about, above, above water, accidental, accompanying.

How do you use "on" in a sentence?

Tomorrow, he will land on the moon.

How do you pronounce "on"?

Pronounced /ɔn/.

Etymology

Etymology 1

Etymology tree Proto-West Germanic *ana Old English on Middle English on English on From Middle English on, from Old English on, an (“on, upon, onto, in, into”), from Proto-West Germanic *ana, from Proto-Germanic *ana (“on, at”), from Proto-Indo-European *h₂en- (“on, onto”). Cognates Cognate with Yola a, an, ana, on (“on”), Saterland Frisian an (“on; at”), West Frisian oan (“on; to, towards”), Cimbrian aan, å (“on, onto”), Dutch aan (“on; at”), Low German an (“on; at, to”), German an (“at, in; on”), Luxembourgish un (“on; at, to”), Yiddish אָן (on, “on, onward”), Danish, Norwegian Nynorsk, and Swedish å (“on”), Elfdalian ą̊ (“on”), Faroese and Icelandic á (“in; on”), Gothic 𐌰𐌽𐌰 (ana, “at, on”); also Umbrian 𐌀𐌌- (am-), 𐌀𐌍- (an-, “up, upon”), Ancient Greek ἀνά (aná, “on, upon”) (whence Greek ανά (aná, “by, through, per”)), Albanian në (“in; on”), Latvian no (“from; out of; for; of; with”), Lithuanian nuo (“from, off; for, of”), Belarusian, Bulgarian, Macedonian, Russian, and Ukrainian на (na, “on”), Czech, Polish, Slovak, and Slovene na (“on”), Serbo-Croatian на, na (“on”), Old Armenian ան- (an-, “at, on, unto”); and from Old Norse upp á: Danish, Norwegian Bokmål, and Swedish på (“on”), Norwegian Nynorsk paa, på (“on”), see upon.

Etymology 2

From Old Norse ón, án (“without”), from Proto-Germanic *ēnu, *ēno, *ino (“without”), from Proto-Indo-European *ḗnu (“without”). Cognate with North Frisian on (“without”), Middle Dutch an, on (“without”), Middle Low German āne (“without”), German ohne (“without”), Gothic 𐌹𐌽𐌿 (inu, “without, except”). Unlikely to be related to Ancient Greek ἄνευ (áneu, “without”), which is likely akin to Proto-Germanic *sundraz instead (whence sunder).

Etymology 3

From Japanese 音読み (on'yomi, literally “sound reading”).

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