Synonyms for Sternocleido Mastoideus (same or very similar meaning)
WordNet sense 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):
sternocleidomastoid, musculus sternocleidomastoideus, sternocleidomastoid muscle
From the ODE community, based on WordNet
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