Dictionary.com
definitions

smooth muscle

noun Anatomy.

involuntary muscle tissue in the walls of viscera and blood vessels, consisting of nonstriated, spindle-shaped cells.

Origin of smooth muscle

First recorded in 1885–90
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
British Dictionary definitions for smooth muscle

smooth muscle

noun

muscle that is capable of slow rhythmic involuntary contractions: occurs in the walls of the blood vessels, alimentary canal, etcCompare striped muscle

Word Origin for smooth muscle

so called because there is no cross-banding on the muscle
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
smooth muscle in Medicine

smooth muscle

n.

Muscle tissue that contracts without voluntary control, having fine myofibrils but lacking transverse striations and found in the walls of internal organs, blood vessels, and hair follicles.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.