What does "deadly" mean?
Subject to death; mortal.
Deadly
/ˈdɛdli/ adj, adv, slang
adj, adv, slang ·Very common ·Middle school level
Meaning at a glance
- Primary sense: Subject to death; mortal.
- Grammar: deadly is listed as adj, adv, slang.
- Nearest alternatives: lethal, mortal, a la mort, abominably.
- Useful contrasts: barely, benign, harmless.
- Usage evidence: We have to abolish all nuclear weapons, because they are deadly to mankind.
How to use "deadly"
- Start with the primary definition, then check the part of speech before placing the word in a sentence.
- Compare nearby synonyms to make sure "deadly" carries the exact meaning, tone, and strength you need.
- 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 "deadly" 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 "deadly" as the right word for your sentence.
If your draft is formal, technical, persuasive, or sensitive, compare "deadly" 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 "deadly" is acting as adj, adv, 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 "lethal" 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 "deadly", 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
Adjective
- 1 Subject to death; mortal. obsolete, rare
"[…]he ſuffred hym ſelfe to be made mortall and dedly, that innocent & gyltles in hym ſelfe: he myght be ſlayne & deye for the gylty man."
- 2 Causing death; lethal.
"But then I had the [massive] flintlock by me for protection. ¶[…]The linen-press and a chest on the top of it formed, however, a very good gun-carriage; and, thus mounted, aim could be taken out of the window[…], and a 'bead' could be drawn upon Molly, the dairymaid, kissing the fogger behind the hedge, little dreaming that the deadly tube was levelled at them."
- 3 Aiming or willing to destroy; implacable; desperately hostile.
"deadly enemies"
- 4 Very accurate (of aiming with a bow, firearm, etc.).
"Its deadly aim at vast distances, which condition of the mechanical power brought has made it the dread of the sepoys, who term it "the gun that kills without making any sound," contrasts strangely with the performances of Brown Bess of old, which at any range beyond a hundred yards was so uncertain in its aim that it has been calculated that the soldier shot away the weight in lead of every man that he hit."
- 5 Very boring. informal
"“I don't mean all of your friends—only a small proportion—which, however, connects your circle with that deadly, idle, brainless bunch—the insolent chatterers at the opera, the gorged dowagers, the worn-out, passionless men, the enervated matrons of the summer capital,[…]!”"
Show 1 more definition
- 6 Excellent, awesome, cool. Ireland, Newfoundland, informal
Adjective
- 1 (of a disease) having a rapid course and violent effect wordnet
- 2 causing or capable of causing death wordnet
- 3 of an instrument of certain death wordnet
- 4 exceedingly harmful wordnet
- 5 involving loss of divine grace or spiritual death wordnet
Show 1 more definition
- 6 extremely poisonous or injurious; producing venom wordnet
Adverb
- 1 Fatally, mortally. obsolete
"[P]erceiving himſelfe deadly wounded by a ſhot received in his body, being by his men perſwaded to come off and retire himſelfe from out the throng, anſwered, he would not now ſo neere his end, beginne to turne his face from his enemie[…]"
- 2 In a way which suggests death.
"Her face suddenly became deadly white."
- 3 Extremely, incredibly.
"Though deadly weary, till ſpectators do / At once part and call them good boys too[…]"
Adverb
- 1 (used as intensives) excessively wordnet
- 2 as if dead wordnet
Synonyms
All synonymsExample
"We have to abolish all nuclear weapons, because they are deadly to mankind."
Common questions
What is a synonym for "deadly"?
Common synonyms include: lethal, mortal, a la mort, abominably, accurate, acutely.
How do you use "deadly" in a sentence?
We have to abolish all nuclear weapons, because they are deadly to mankind.
How do you pronounce "deadly"?
Pronounced /ˈdɛdli/.
Etymology
From Middle English dedly, dedlych, dedlich, from Old English dēadlīċ (adjective), from Proto-West Germanic *dauþalīk, from Proto-Germanic *dauþalīkaz (“deadly”, literally “deathly”). By surface analysis, dead + -ly. Cognate with Saterland Frisian dodelk (“deadly”), West Frisian deadlik (“deadly”), Dutch dodelijk (“deadly”), German tödlich (“deadly”), Swedish dödlig (“deadly, fatal, mortal”), Icelandic dauðlegur (“mortal”). The adverb is from Middle English dedliche, from Old English dēadlīċe (adverb), from the adjective.