/ Dictionary / Index A apsis: Meaning and Definition of Find definitions for: ap•sis Pronunciation: (ap'sis), [key] — pl. -si•des either of two points in an eccentric orbit, onefarthest from the center of attraction, the othernearest to the center of attraction. an apse. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: apsis (Thesaurus) apsidiole Ap star 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