/ Dictionary / Index P petcock: Meaning and Definition of Find definitions for: pet•cock Pronunciation: (pet'kok"), [key] — n. a small valve or faucet, as for draining off excess or waste material from the cylinder of a steam engine or an internal-combustion engine. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: petcock (Thesaurus) Petavius Pet.E. Related Content Daily Word Quiz: miscreant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language