heat unit heat sum • heat up · · · Info · Definitions · Synonyms · Characters · · heat unit · · Text Common · · Latin · · Scripts 9 · · Length 3 · · Syllables Definitions · · · (noun) a unit of measurement for work. Synonyms: work unit, heat unit, energy unit. · · Noun Definition 1 Synonyms · · · work unit · · Synonym 1 energy unit · · Synonym 2 Characters · · space U+0020 a latin small letter a U+0061 e latin small letter e U+0065 h latin small letter h U+0068 i latin small letter i U+0069 n latin small letter n U+006E t latin small letter t U+0074 u latin small letter u U+0075