/ Dictionary / Index C Cleanthes: Meaning and Definition of Find definitions for: Cle•an•thes Pronunciation: (klē-an'thēz), [key] — n. c300–232? b.c., Greek Stoic philosopher. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: cleanthes (Thesaurus) clean sweep cleanup Related Content Daily Word Quiz: impetuous Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language