Fly

/flaɪ/ adj, name, noun, verb, slang

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

Meaning at a glance

  • Primary sense: Any insect of the order Diptera; characterized by having two wings (except for some wingless species), also called true flies.
  • Grammar: fly is listed as adj, name, noun, verb, slang.
  • Nearest alternatives: flee, fly ball, abscond, abscond.
  • Useful contrasts: footed, amtrak, backpacking.
  • Usage evidence: I wonder if they don't have meetings anymore where strong words fly and everyone goes at each other tooth and nail.

How to use "fly"

  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 "fly" 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 "fly" 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 "fly" as the right word for your sentence.

If your draft is formal, technical, persuasive, or sensitive, compare "fly" 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 "fly" is acting as adj, name, noun, 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 "flee" 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 "fly", 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
    Any insect of the order Diptera; characterized by having two wings (except for some wingless species), also called true flies.

    "Devils Lake is where I began my career as a limnologist in 1964, studying the lake’s neotenic salamanders and chironomids, or midge flies. […] The Devils Lake Basin is an endorheic, or closed, basin covering about 9,800 square kilometers in northeastern North Dakota."

  2. 2
    The action of flying; flight. obsolete
  3. 3
    A wing. Northern-England, Scotland

    "The bullet barely grazed the wild fowl's fly."

  4. 4
    Alternative form of vly (“swamp (in New York)”). alt-of, alternative

    "June 8, 1708, John Cock and William Nottingham desire 100 acres each [...] Isaac Davis desied a conveyance for the "greenbush" fly or swamp that he hath drained near his land, in the Jaagh Creupel-bosh."

  5. 5
    (baseball) a hit that flies up in the air wordnet
Show 34 more definitions
  1. 6
    Especially, any of the insects of the family Muscidae, such as the common housefly (other families of Diptera include mosquitoes and midges).

    "When you're well enough off so's you don't have to fret about anything but your heft or your diseases you begin to get queer, I suppose. And the queerer the cure for those ailings the bigger the attraction. A place like the Right Livers' Rest was bound to draw freaks, same as molasses draws flies."

  2. 7
    An act of flying.

    "There was a good wind, so I decided to give the kite a fly."

  3. 8
    two-winged insects characterized by active flight wordnet
  4. 9
    Any similar but not closely related insect, such as a dragonfly, butterfly, or gallfly.
  5. 10
    A fly ball.
  6. 11
    an opening in a garment that is closed by a zipper or by buttons concealed under a fold of cloth wordnet
  7. 12
    A lightweight fishing lure resembling an insect.

    "I went on trying for fish along the western bank down the river, but only small trout rose at my flies, and a score was the total catch."

  8. 13
    Ellipsis of fly route. abbreviation, alt-of, ellipsis
  9. 14
    fisherman's lure consisting of a fishhook decorated to look like an insect wordnet
  10. 15
    A chest exercise performed by moving extended arms from the sides to in front of the chest. (also flye)
  11. 16
    A piece of canvas that covers the opening at the front of a tent.
  12. 17
    flap consisting of a piece of canvas that can be drawn back to provide entrance to a tent wordnet
  13. 18
    The butterfly stroke (plural is normally flys).
  14. 19
    The sloping or roof part of the canvas of a tent. India, obsolete

    "[T]he main part of the operation of pitching the tent, consisting of raising the flies, may be performed, and shelter afforded, without the walls, &c., being present."

  15. 20
    A witch's familiar. obsolete

    "a trifling fly, none of your great familiars"

  16. 21
    A strip of material (sometimes hiding zippers or buttons) at the front of a pair of trousers, pants, underpants, bootees, etc. often, plural

    "Ha-ha! Your fly's undone!"

  17. 22
    A parasite. obsolete

    "The fly that plays too near the flame burns in it."

  18. 23
    The free edge of a flag.
  19. 24
    A simple dance in which the hands are shaken in the air, popular in the 1960s.
  20. 25
    The horizontal length of a flag.
  21. 26
    A butterfly (combination of four options).
  22. 27
    An exercise that involves wide opening and closing of the arms perpendicular to the shoulders.
  23. 28
    The part of a weather vane pointing the direction from which the wind blows.
  24. 29
    That part of a compass on which the points are marked; the compass card.

    "to the fly of the compass, which before was made equal, I was still constrained to put some small piece of wire on the south part there"

  25. 30
    Two or more vanes set on a revolving axis, to act as a fanner, or to equalize or impede the motion of machinery by the resistance of the air, as in the striking part of a clock.
  26. 31
    Ellipsis of flywheel. abbreviation, alt-of, ellipsis
  27. 32
    A type of small, light, fast horse-drawn carriage that can be hired for transportation (sometimes pluralised flys). historical

    "A fly carried him rapidly to Lady Clavering’s house from the station […]"

  28. 33
    In a knitting machine, the piece hinged to the needle, which holds the engaged loop in position while the needle is penetrating another loop; a latch.
  29. 34
    The pair of arms revolving around the bobbin, in a spinning wheel or spinning frame, to twist the yarn.
  30. 35
    A shuttle driven through the shed by a blow or jerk.
  31. 36
    The person who took the printed sheets from the press. historical
  32. 37
    A vibrating frame with fingers, attached to a power printing press for doing the same work. historical
  33. 38
    One of the upper screens of a stage in a theatre.

    "It was as if I been idling on a brightly lit stage-set of a country garden, ripe with every sort of pastoral fancy, and then had turned a flat and come on the stagehands and the wings, the propped sets, the men working in the flies—all the dark mechanics that produced the pretty picture the audience saw."

  34. 39
    Waste cotton.
Verb
  1. 1
    To travel through the air, another gas, or a vacuum, without being in contact with a grounded surface. intransitive

    "Birds of passage fly to warmer regions as it gets colder in winter."

  2. 2
    To hit a fly ball; to hit a fly ball that is caught for an out. Compare ground (verb) and line (verb). intransitive

    "Jones flied to right in his last at-bat."

  3. 3
    decrease rapidly and disappear wordnet
  4. 4
    To flee, to escape (from). ambitransitive, archaic, poetic

    "Fly, my lord! The enemy are upon us!"

  5. 5
    change quickly from one emotional state to another wordnet
Show 20 more definitions
  1. 6
    To cause to fly (travel or float in the air): to transport via air or the like. ergative, transitive

    "Charles Lindbergh flew his airplane The Spirit of St. Louis across the Atlantic ocean."

  2. 7
    hit a fly wordnet
  3. 8
    To travel or proceed very fast; to hasten. intransitive

    "He flew down the hill on his bicycle."

  4. 9
    transport by aeroplane wordnet
  5. 10
    To move suddenly, or with violence; to do an act suddenly or swiftly. intransitive

    "a door flies open"

  6. 11
    be dispersed or disseminated wordnet
  7. 12
    To proceed with great success. intransitive

    "His career is really flying at the moment."

  8. 13
    travel in an airplane wordnet
  9. 14
    To be accepted, come about or work out. colloquial, intransitive

    "Let's see if that idea flies."

  10. 15
    move quickly or suddenly wordnet
  11. 16
    To display (a flag) on a flagpole. ergative, transitive
  12. 17
    travel over (an area of land or sea) in an aircraft wordnet
  13. 18
    To hunt with a hawk. transitive

    "We'll fly the partridge, or go rouse the deer."

  14. 19
    cause to fly or float wordnet
  15. 20
    To be in the winged adult stage. intransitive

    "This species flies from late summer until frost."

  16. 21
    travel through the air; be airborne wordnet
  17. 22
    operate an airplane wordnet
  18. 23
    pass away rapidly wordnet
  19. 24
    run away quickly wordnet
  20. 25
    display in the air or cause to float wordnet
Adjective
  1. 1
    Quick-witted, alert, mentally sharp. dated, slang

    "be assured, O man of sin—pilferer of small wares and petty larcener—that there is an eye within keenly glancing from some loophole contrived between accordions and tin breastplates that watches your every movement, and is "fly,"— to use a term peculiarly comprehensible to dishonest minds—to the slightest gesture of illegal conveyancing."

  2. 2
    Clandestine, surreptitious slang

    "Some say God was an alien that tampered with our DNA, the 3 kings followed ufos & Mary had a fly shag 🤔🤫"

  3. 3
    Well dressed, smart in appearance; in style, cool. slang

    "He's pretty fly."

  4. 4
    Beautiful; displaying physical beauty. slang

    "[Rahiem] My name brings peace and tranquility / So all the fly ladies' hearts can run free"

Adjective
  1. 1
    (British informal) not to be deceived or hoodwinked wordnet
Proper Noun
  1. 1
    A river in Papua New Guinea
  2. 2
    A surname.

Synonyms

All synonyms
fleefly ballabscondabscondabsquatulateadvance

Example

"I wonder if they don't have meetings anymore where strong words fly and everyone goes at each other tooth and nail."

Common questions

What does "fly" mean?

Any insect of the order Diptera; characterized by having two wings (except for some wingless species), also called true flies.

What is a synonym for "fly"?

Common synonyms include: flee, fly ball, abscond, abscond, absquatulate, advance.

How do you use "fly" in a sentence?

I wonder if they don't have meetings anymore where strong words fly and everyone goes at each other tooth and nail.

How do you pronounce "fly"?

Pronounced /flaɪ/.

Etymology

Etymology 1

From Middle English flye, flie, from Old English flȳġe, flēoge (“a fly”), from Proto-Germanic *fleugǭ (“a fly”), from Proto-Indo-European *plewk- (“to fly”). Cognate with Scots flee, Saterland Frisian Fljooge, Dutch vlieg, German Low German Fleeg, German Fliege, Danish flue, Norwegian Bokmål flue, Norwegian Nynorsk fluge, Swedish fluga, Icelandic fluga.

Etymology 2

From Middle English flien, from Old English flēogan, from Proto-Germanic *fleuganą (compare Saterland Frisian fljooge, Dutch vliegen, Low German flegen, German fliegen, Danish flyve, Norwegian Nynorsk flyga), from Proto-Indo-European *plewk- (*plew-k-, “to fly”) (compare Lithuanian plaũkti ‘to swim’), enlargement of *plew- (“flow”). More at flee and flow.

Etymology 3

From Middle English flye (“flying, flight”), from Old English flyge (“flying, flight”), from Proto-Germanic *flugiz.

Etymology 4

Uncertain; probably from the verb or noun.

Etymology 5

Related to German Flügel (“a wing”), Dutch vleugel (“a wing”), Swedish flygel (“a wing”).

Etymology 6

The Fly was first discovered by Europeans in 1845 when Francis Blackwood, commanding the corvette HMS Fly, surveyed the western coast of the Gulf of Papua. The river was named after his ship and he proclaimed that it would be possible for a small steam-powered boat to travel up the mighty river.

More for "fly"

Synonyms

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