/ Dictionary / Index B billon: Meaning and Definition of Find definitions for: bil•lon Pronunciation: (bil'un), [key] — n. an alloy used in coinage, consisting of gold or silver with a larger amount of base metal. an alloy of silver with copper or the like, used for coins of small denomination. any coin struck from such an alloy. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. bill of sale billow 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