/ Dictionary / Index B by-product: Meaning and Definition of Find definitions for: by-prod•uct Pronunciation: (bī'prod"ukt), [key] — n. a secondary or incidental product, as in a process of manufacture. the result of another action, often unforeseen or unintended. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: by-product (Thesaurus) by-plot Byrd 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