/ Dictionary / Index B backflow: Meaning and Definition of Find definitions for: back•flow Pronunciation: (bak'flō"), [key] — n. a flow of a liquid opposite to the usual or desired direction. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: backflow (Thesaurus) back float backflow valve Related Content Daily Word Quiz: ontiguous Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language