/ Dictionary / Index A Ap star: Meaning and Definition of Find definitions for: Ap star Pronunciation: (ā'pē'), [key] — Astron. Astron. a peculiar A star whose emission spectrum is characterized by abnormally strong lines of certain ionized metals. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. apsis Apsu 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