lethal

¹le·thal

adjective \ˈlē-thəl\

Definition of LETHAL

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>

— le·thal·i·ty \lē-ˈtha-lə-tē\ noun

— le·thal·ly \ˈlē-thə-lē\ adverb

Examples of LETHAL

1. a potentially lethal dose of a drug
2. He was sentenced to death by lethal injection.

Origin of LETHAL

Latin letalis, lethalis, from letum death

First Known Use: circa 1604

Related to LETHAL

Synonyms

baleful, deathly, fatal, fell, killer, deadly, mortal, murderous, pestilent, terminal, vital

Antonyms

healthful, healthy, nonfatal, nonlethal, wholesome

Related Words

baneful, deleterious, destructive, harmful, injurious, noxious, pernicious, truculent; infectious, infective, pestilential, poisonous, sublethal, toxic, virulent; dangerous, grave, grievous, hazardous, jeopardizing, menacing, parlous, perilous, risky, serious, threatening, ugly, unhealthy, unsound; bloody, internecine, sanguinary, sanguine

Near Antonyms

beneficial, restorative, salubrious, salutary; alleviative, corrective, curative, remedial, tonic; advantageous, beneficial, useful; nonpoisonous, nontoxic, safe

See Synonym Discussion at deadly

²lethal

noun

Definition of LETHAL

1

: an abnormality of genetic origin causing the death of the organism possessing it

2

: lethal gene

First Known Use of LETHAL

1917