sternocleidomastoid muscle meaning and definition

STERNOCLEIDOMASTOID MUSCLE noun

Definition of sternocleidomastoid muscle (noun)

1. 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
   • synonyms: musculus sternocleidomastoideus, sternocleido mastoideus, sternocleidomastoid