/ Dictionary / Index P plagiocephaly: Meaning and Definition of Find definitions for: pla•gi•o•ceph•a•ly Pronunciation: (plā"jē-u-sef'u-lē), [key] — n. Med. a deformity of the skull in which one side is more developed in the front, and the other side is more developed in the rear. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: plagiocephaly (Thesaurus) plagio- plagioclase Related Content Daily Word Quiz: deleterious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language