1
a
: of, relating to, or causing death
death by lethal injection
b
: capable of causing death
lethal chemicals
2
: gravely damaging or destructive : devastating
a lethal attack on his reputation
3
: very potent or effective
a lethal fastball
also
: having a high alcohol content
a lethal rum punch
1
: an abnormality of genetic origin causing the death of the organism possessing it
2
Synonyms
Examples of lethal in a Sentence
Adjective
a potentially lethal dose of a drug
He was sentenced to death by lethal injection.
Recent Examples on the Web
Andi Babineau, CNN, 27 Nov. 2024
This bill would allow doctors to prescribe lethal drugs to patients who meet certain criteria.
—The Editors, National Review, 27 Nov. 2024
Kylie Bourne, Discover Magazine, 14 Sep. 2015
Almost 8 of 10 lethal overdose victims had no contact with the agency before their deaths, the report found.
—Washington Post, 4 Sep. 2020
See all Example Sentences for lethal 
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Adjective
Police began investigating James Craig in the death of his wife after a business partner informed them Craig had ordered potassium cyanide to be sent to his dental practice, their affidavit said, drawing the concern of the partner because the chemical is highly lethal if ingested.
—Andi Babineau, CNN, 27 Nov. 2024
This bill would allow doctors to prescribe lethal drugs to patients who meet certain criteria.
—The Editors, National Review, 27 Nov. 2024
Noun
There are already concerns in Australia about the rate of escalation of force at some protests and about the use of less-than-lethal weaponry itself.
—Kylie Bourne, Discover Magazine, 14 Sep. 2015
Almost 8 of 10 lethal overdose victims had no contact with the agency before their deaths, the report found.
—Washington Post, 4 Sep. 2020
See all Example Sentences for lethal
Dictionary Entries Near lethal
Cite this Entry
“Lethal.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/lethal. Accessed 1 Dec. 2024.
Copy CitationKids Definition
lethal
2 of 2 nounMedical Definition
lethal
1 of 2 adjective
le·thal
ˈlē-thəl 
: of, relating to, or causing death
a lethal injury
also
: capable of causing death
lethal chemicals
a lethal dose
lethally
adverb
lethal
2 of 2 noun1
: an abnormality of genetic origin causing the death of the organism possessing it usually before maturity
2
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