/ Dictionary / Index G gallon: Meaning and Definition of Find definitions for: gal•lon Pronunciation: (gal'un), [key] — n. a common unit of capacity in English-speaking countries, equal to four quarts, the U.S. standard gallon being equal to 231 cubic inches (3.7853 liters), and the British imperial gallon to 277.42 cubic inches (4.546 liters). Abbr.: gal. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: gallon (Thesaurus) galloglass gallonage 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