/ Dictionary / Index C colloidal: Meaning and Definition of Find definitions for: col•loi•dal Pronunciation: (ku-loid'l), [key] — adj. Physical Chem. pertaining to or of the nature of a colloid: colloidal gold and silver. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: colloidal (Thesaurus) colloid colloidal suspension Related Content Daily Word Quiz: eureka Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language