/ Dictionary / Index P protective colloid: Meaning and Definition of Find definitions for: protec'tive col'loid Pronunciation: [key] — Physical Chem. Physical Chem. a lyophilic colloid added to a lyophobic sol to lessen its sensitivity to the precipitating effect of an electrolyte. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. protective protective coloration Related Content Daily Word Quiz: deleterious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language