The Collaborative International Dictionary of English v.0.48:
Plagiocephaly \Pla`gi*o*ceph"a*ly\, n. (Anat.) Oblique lateral deformity of the skull. [1913 Webster]WordNet (r) 3.0 (2006):
plagiocephaly n 1: congenital malformation of the skull in which the main axis of the skull is oblique