/ Dictionary / Index C cross ratio: Meaning and Definition of Find definitions for: cross' ra'tio Pronunciation: [key] — Geom. Geom. a ratio relating four points in the real or complex plane. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. crossrail cross-react Related Content Daily Word Quiz: wary Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language