muscle that is capable of slow rhythmic involuntary contractions: occurs in the walls of the blood vessels, alimentary canal, etc
Compare striped muscle
Word origin
so called because there is no cross-banding on the muscle
smooth muscle in American English
a contractile type of muscle tissue controlled by the involuntary nervous system, occurring in the walls of the uterus, stomach, intestines, blood vessels, etc., and characterized by nonstriated, spindle-shaped cells