lethal
Americanadjective
-
able to cause or causing death
-
of or suggestive of death
Synonym Usage
See fatal.
Other Word Forms
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”; see Lethe ( def. )
Explanation
Lethal refers to anything dangerous enough to cause death. The cobra's venom is so lethal that if you get bitten and can't find the antidote, it's lights out forever. Poisonous spiders, guns, knives, and radiation — all of these things can be lethal because they have the ability to kill. Even some substances that on their own aren't dangerous can become lethal in large quantities. Eating a peanut butter sandwich won't hurt most people, but it can be lethal to those with a nut allergy. Words like deadly and fatal have meanings that are similar to lethal.
Vocabulary lists containing lethal
100 SAT Words Beginning with "J," "K," and "L"
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A Long Way Gone
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Silent Spring
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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.
Native American tradition speaks of a type of shapeshifter known as a tolik, or human bear, who can cast lethal spells on their enemies.
From The Wall Street Journal • Jun. 11, 2026
It possesses the most lethal and far-flung military; it controls the leading currency; its leaders’ words and deeds are more closely observed and analyzed than those of any other leaders.
From Slate • Jun. 8, 2026
In Sasaki’s best starts, the elevated velocity and pitch mix makes the right-hander lethal, giving him extended runway to pitch further into the game.
From Los Angeles Times • Jun. 6, 2026
The broken leg was another serious disruption for a player meant to provide Liverpool with a lethal spearhead.
From BBC • May 30, 2026
Tom had discovered that five-day-old Marburg-virus particles are just as lethal and infective as fresh particles.
From "The Hot Zone" by Richard Preston
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
