lethal dose lethal agent • lethal gene · · · Info · Definitions · Characters · · lethal dose · · Text Common · · Latin · · Scripts 11 · · Length 3 · · Syllables Definitions · · · (noun) the size dose that will cause death. Synonyms: lethal dose. · · Noun Definition 1 Characters · · space U+0020 a latin small letter a U+0061 d latin small letter d U+0064 e latin small letter e U+0065 h latin small letter h U+0068 l latin small letter l U+006C o latin small letter o U+006F s latin small letter s U+0073 t latin small letter t U+0074