/ Dictionary / Index B by-blow: Meaning and Definition of Find definitions for: by-blow Pronunciation: (bī'blō"), [key] — n. an incidental or accidental blow. an illegitimate child; bastard. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: by-blow (Thesaurus) Byblos by cracky Related Content Daily Word Quiz: careening Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language