The Collaborative International Dictionary of English v.0.48:
Acromion \A*cro"mi*on\, n. [Gr. ?; 'a`kros extreme + ? shoulder: cf. F. acromion.] (Anat.) The outer extremity of the shoulder blade. [1913 Webster]WordNet (r) 3.0 (2006):
acromion n 1: the outermost point of the spine of the shoulder blade [syn: acromion, acromial process]