/ Dictionary / Index M Mellon: Meaning and Definition of Find definitions for: Mel•lon Pronunciation: (mel'un), [key] 1855–1937, U.S. financier: Secretary of the Treasury 1921–32. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: mellon (Thesaurus) mellitum mellophone Related Content Daily Word Quiz: supercilious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language