heart muscle heart murmur • heartnut · · · Info · Definitions · Synonyms · Characters · · heart muscle · · Text Common · · Latin · · Scripts 12 · · Length 3 · · Syllables Definitions · · · (noun) the muscle tissue of the heart; adapted to continued rhythmic contraction. Synonyms: cardiac muscle, heart muscle. · · Noun Definition 1 Synonyms · · · cardiac muscle · · Synonym 1 Characters · · space U+0020 a latin small letter a U+0061 c latin small letter c U+0063 e latin small letter e U+0065 h latin small letter h U+0068 l latin small letter l U+006C m latin small letter m U+006D r latin small letter r U+0072 s latin small letter s U+0073 t latin small letter t U+0074 u latin small letter u U+0075