lethal gene lethal dose • lethality · · · Info · Definitions · Characters · · lethal gene · · Text Common · · Latin · · Scripts 11 · · Length 3 · · Syllables Definitions · · · (noun) any gene that has an effect that causes the death of the organism at any stage of life. Synonyms: lethal gene. · · Noun Definition 1 Characters · · space U+0020 a latin small letter a U+0061 e latin small letter e U+0065 g latin small letter g U+0067 h latin small letter h U+0068 l latin small letter l U+006C n latin small letter n U+006E t latin small letter t U+0074