/ Dictionary / Index O OTC: Meaning and Definition of Find definitions for: OTC Pronunciation: [key] Officers' Training Corps. over-the-counter. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: otc (Thesaurus) OTB -ote Related Content Daily Word Quiz: acquiesce Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language