/ Dictionary / Index O ounce: Meaning and Definition of Find definitions for: ounce Pronunciation: (ouns), [key] — n. a unit of weight equal to 437.5 grains or pound (28.349 grams) avoirdupois. a unit of 480 grains, pound (31.103 grams) troy or apothecaries' weight. a fluid ounce. a small quantity or portion. ounce Pronunciation: (ouns), [key] — n. See Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: ounce (Thesaurus) Oulu ouncer 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