/ Dictionary / Index M monochasium: Meaning and Definition of Find definitions for: mon•o•cha•si•um Pronunciation: (mon"u-kā'zhē-um, -zhum, -zē-um), [key] — pl. -si•a a form of cymose inflorescence in which the main axis produces only a single branch. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Monoceros monochloride Related Content Daily Word Quiz: abominable Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language