/ Dictionary / Index A apse line: Meaning and Definition of Find definitions for: apse' line" Pronunciation: [key] — Astron. Astron. See Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. apse apsidal motion 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