half life half-liberal • half-life · · · Info · Definitions · Synonyms · Characters · · half life · · Text Common · · Latin · · Scripts 9 · · Length 2 · · Syllables Definitions · · · (noun) the time required for something to fall to half its initial value (in particular, the time for half the atoms in a radioactive substance to disintegrate). Synonyms: half life, half-life. · · Noun Definition 1 Synonyms · · · half-life · · Synonym 1 Characters · · space U+0020 a latin small letter a U+0061 e latin small letter e U+0065 f latin small letter f U+0066 h latin small letter h U+0068 i latin small letter i U+0069 l latin small letter l U+006C