/ Dictionary / Index O oppidan: Meaning and Definition of Find definitions for: op•pi•dan Pronunciation: (op'i-dun), [key] — adj. of a town; urban. —n. a townsman. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Oppenheimer oppilate 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