/ Dictionary / Index C cert.: Meaning and Definition of Find definitions for: cert. Pronunciation: [key] certificate. certification. certified. certify. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: cert (Thesaurus) Cerro Tololo Inter-American Observatory certain Related Content Daily Word Quiz: abstain Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language