heat engine heat energy • heat-engine cycle · · · Info · Definitions · Characters · · heat engine · · Text Common · · Latin · · Scripts 11 · · Length 3 · · Syllables Definitions · · · (noun) any engine that makes use of heat to do work. Synonyms: heat engine. · · 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 i latin small letter i U+0069 n latin small letter n U+006E t latin small letter t U+0074