a·cro·mi·on 
(ə-krōmē-ən)
(ə-krōmē-ən)n. pl. a·cro·mi·a (mē-ə)
The outer end of the scapula to which the collarbone is attached.
[New Latin acrōmion, from Greek akrōmion : akros, extreme; see ak- in the Appendix of Indo-European roots + ōmos, shoulder.]
a·cromi·al adj.