/ Dictionary / Index C Clusium: Meaning and Definition of Find definitions for: Clu•si•um Pronunciation: (kl'sē-um), [key] — n. ancient name of Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Clurman cluster Related Content Daily Word Quiz: agitated Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language