involuntary muscle involuntary • involuntary trust · · · Info · Definitions · Synonyms · Characters · · involuntary muscle · · Text Common · · Latin · · Scripts 18 · · Length 7 · · Syllables Definitions · · · (noun) a muscle that contracts without conscious control and found in walls of internal organs such as stomach and intestine and bladder and blood vessels (excluding the heart). Synonyms: smooth muscle, involuntary muscle. · · Noun Definition 1 Synonyms · · · smooth 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 i latin small letter i U+0069 l latin small letter l U+006C m latin small letter m U+006D n latin small letter n U+006E o latin small letter o U+006F 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 v latin small letter v U+0076 y latin small letter y U+0079