from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Either of two muscles of the neck that serve to flex and rotate the head.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Relating to or involving the sternum, the clavicle and the mastoid process.
- n. The sternocleidomastoid muscle
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. one of two thick muscles running from the sternum and clavicle to the mastoid and occipital bone; turns head obliquely to the opposite side; when acting together they flex the neck and extend the head
stern(um) + Greek kleis, kleid-, collarbone + mastoid.(American Heritage® Dictionary of the English Language, Fourth Edition)