/ Dictionary / Index C CLU: Meaning and Definition of Find definitions for: CLU Pronunciation: [key] Civil Liberties Union. C.L.U. Pronunciation: [key] Chartered Life Underwriter. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. clr. club Related Content Daily Word Quiz: reiterate Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language