/ Dictionary / Index C cfs: Meaning and Definition of Find definitions for: cfs Pronunciation: [key] cubic feet per second. CFS Pronunciation: [key] chronic fatigue syndrome. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: cfs (Thesaurus) CFR CFT Related Content Daily Word Quiz: alacrity Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language