/ Dictionary / Index O open cover: Meaning and Definition of Find definitions for: o'pen cov'er Pronunciation: [key] — Math. Math. a cover of a set consisting entirely of open sets. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. open couplet open-cut Related Content Daily Word Quiz: panacea Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language