/ Dictionary / Index E equatorial plane: Meaning and Definition of Find definitions for: e'quato'rial plane' Pronunciation: [key] — Astron. Astron. the plane passing through the equator of the earth or another celestial body. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Equatorial Guinea equatorial plate Related Content Daily Word Quiz: spectral Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language