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Added 9 October 2026

deadly

/ˈdɛdli/ adjective

In Latin: mortifer, lētālis, exitiālis Wiktionary

adjective Definition from Wiktionary (CC BY-SA). Pronunciation from Wiktionary, via Kaikki.org. More about deadly at Wordnik → Where our words come from →

Subject to death; mortal.
Causing death; lethal.
Aiming or willing to destroy; implacable; desperately hostile.
deadly enemies

adverb

Fatally, mortally.
In a way which suggests death.
Her face suddenly became deadly white.
Extremely, incredibly.

Origin

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.

From Wiktionary, via Kaikki.org (CC BY-SA)

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