/ Dictionary / Index B binary fission: Meaning and Definition of Find definitions for: bi'nary fis'sion Pronunciation: [key] — Biol. Biol. fission into two organisms approximately equal in size. Cf. multiple fission. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. binary digit binary form Related Content Daily Word Quiz: secular Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language