/ Dictionary / Index P perlite: Meaning and Definition of Find definitions for: per•lite Pronunciation: (pûr'līt), [key] — n. Petrog. a volcanic glass in which concentric fractures impart a distinctive structure resembling masses of small spheroids, used as a plant growth medium. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Perlis perlocutionary Related Content Daily Word Quiz: cautious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language