Word
deadly
Phoneticsdead·ly, stress on the first syllable
US/ˈdɛdɫi/
UK/dˈɛdli/
Definitions
01lethal
B2 · Upper Intermediate
adj. able to cause death.
adj. capable of causing death; lethal or fatal in effect.
Español:exicial
“The cobra has a deadly bite that can kill a person in hours.”
“The researchers discovered that even a minute dose of the toxin proved deadly to most mammals within the ecosystem.”
02extremely accurate
B2 · Upper Intermediate
adj. very accurate and effective, especially when aiming a weapon or a ball.
adj. highly accurate or effective; unerring in aim or execution.
“The striker has a deadly shot that rarely misses the goal.”
“His reputation as a deadly marksman ensured that few dared to challenge him in the regional competition.”
Antonyms
03very boring
C1 · Advanced Informal
adj. extremely dull or uninteresting.
adj. extremely dull, tedious, or monotonous. Informal in register.
“The three-hour lecture on tax law was absolutely deadly.”
“The meeting was so deadly that several board members were visibly struggling to remain awake during the financial presentation.”
Antonyms
04excellent
C2 · Proficiency Informal · Dialect
adj. very good or cool.
adj. excellent, impressive, or highly desirable. Primarily used in Irish and Newfoundland dialects.
“That new jacket you bought is deadly.”
“The local band played a deadly set at the pub last night, drawing a massive crowd from the surrounding villages.”
Teaching tip
This sense is specific to certain regions like Ireland; learners should be aware it may not be understood in the US or UK.
05extremely
B2 · Upper Intermediate
adv. used to emphasize an adjective, meaning 'very' or 'completely'.
adv. used as an intensifier meaning extremely or utterly; often collocates with 'serious', 'dull', or 'quiet'.
“The room went deadly quiet when the principal walked in.”
“The CEO was deadly serious when she announced that the company would be restructuring its entire European division.”
Usage
Commonly used in the fixed phrase 'deadly serious'.
Synonyms
Collocations
Common phrases and expressions where native English speakers use the word “deadly” in context.
Verb
01. prove deadly
“Even a small mistake in these extreme weather conditions can prove deadly for hikers.”
verb + adj
Adjective
02. deadly weapon
“The police officer warned that a car can be a deadly weapon if driven recklessly.”
adj + noun
03. deadly accurate
“The striker's shooting was deadly accurate, hitting the top corner of the net every time.”
adv + adj
04. deadly poison
“The bright colors of the frog serve as a warning that it contains a deadly poison.”
adj + noun
05. deadly serious
“I thought he was joking at first, but his face showed he was deadly serious.”
adv + adj
Noun
06. deadly virus
“Scientists are working around the clock to develop a vaccine for the deadly virus.”
adj + noun
07. deadly silence
“A deadly silence filled the room after the CEO announced the mass layoffs.”
adj + noun
08. deadly attacks
09. deadly earthquake
Real-World Examples
“An Australian woman, Erin Patterson, was found guilty of murdering three of her husband’s relatives and trying to kill a fourth by serving them deadly mushrooms.” “Deivi Delfín and his brother moved to Colombia after a quake in Venezuela killed their mother, but were caught in another deadly disaster.” 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.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.
Word family
ADJECTIVE
- Exam level
- CambridgeCambridgeCambridge English QualificationsThe exam suite from Cambridge University Press & Assessment, from A1 Movers up to C2 Proficiency. The benchmark names double as CEFR labels.B2 FirstIELTSIELTSInternational English Language Testing SystemThe 0–9 band test co-owned by the British Council, IDP, and Cambridge. Used for university entry, work, and migration.5.5–6.5TOEFL iBTTOEFL iBTTest of English as a Foreign Language, Internet-Based TestETS's academic English test, the standard route for US university admissions. Scored 0–120, with a 1–6 scale since 2026.1–6 scale: 4.0–4.572–94TOEICTOEICTest of English for International CommunicationETS's workplace English test, big in Japan and Korea. Listening & Reading scores 10–990 and tops out at C1.785–944
- Frequency
- Common
- Level
- B2 · Upper IntermediateOxford
- Updated
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QR code
englishreference.com/q/deadly
Traducciones: Kaikki.org (Wiktionary), CC BY-SA 4.0