LETHAL
deadly, lethal
(adjective) of an instrument of certain death; “deadly poisons”; “lethal weapon”; “a lethal injection”
Source: WordNet® 3.1
Etymology 1
Adjective
lethal (comparative more lethal, superlative most lethal)
Deadly; mortal; fatal.
Noun
lethal (plural lethals)
Any weapon that causes death.
Antonym: non-lethal
(genetics) An allele that causes the death of the organism that carries it.
Etymology 2
Abbreviation of “lauric acid ethereal salt”, so called because it occurs in the ethereal salt of lauric acid.
Noun
lethal (uncountable)
(chemistry) One of the higher alcohols of the paraffine series obtained from spermaceti as a white crystalline solid.
Source: Wiktionary
Leth"al, n. Etym: [Lauric + ether + alcohol.] (Chem.)
Definition: One of the higher alcohols of the paraffine series obtained
from spermaceti as a white crystalline solid. It is so called because
it occurs in the ethereal salt of lauric acid.
Le"thal, a. Etym: [L. lethalis, letalis, fr. lethum, letum, death:
cf. F. léthal.]
Definition: Deadly; mortal; fatal. "The lethal blow." W. Richardson.
– Le"thal*ly, adv.
Source: Webster’s Unabridged Dictionary 1913 Edition