Dictionary.com
Thesaurus.com
Synonyms

lethal

American  
[lee-thuhl] / ˈli θəl /

adjective

  1. of, relating to, or causing death; deadly; fatal: a lethal dose.

    a lethal weapon;

    a lethal dose.

  2. made or carried out to cause death: a lethal attack.

    a lethal chamber;

    a lethal attack.

  3. causing great harm or destruction.

    The disclosures were lethal to his candidacy.


lethal British  
/ liːˈθælɪtɪ, ˈliːθəl /

adjective

  1. able to cause or causing death

  2. of or suggestive of death

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Related Words

See fatal.

Other Word Forms

  • hyperlethal adjective
  • lethality noun
  • lethally adverb
  • lethalness noun
  • nonlethal adjective
  • nonlethally adverb
  • semilethal adjective

Etymology

Origin of lethal

First recorded in 1575–85; from Latin lētālis, equivalent to lēt(um) “death” + -ālis -al 1; spelling (hence pronunciation) with -h- by association with Greek lḗthē “oblivion”; Lethe ( def. )

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

That unease about working on lethal technology is just one of many factors contributing to an ongoing skills gap in the defence sector.

From BBC

After a few months searching for confidence and his top level, by the time 2025 began Mbappe was back to his lethal best.

From Barron's

Although he comes across as lethally ineffective—desperation is not the way to please an audience—the movie positions his act as a hit.

From The Wall Street Journal

By eschewing inefficient long twos, Curry and Harden became the two most lethal scorers in the NBA.

From The Wall Street Journal

Melanoma is the most lethal form of skin cancer and is responsible for about 11,000 deaths in the U.S. each year.

From Science Daily