/ Dictionary / Index P perthite: Meaning and Definition of Find definitions for: perth•ite Pronunciation: (pûr'thīt), [key] — n. Mineral a variety of feldspar containing irregular bands of albite in microcline. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Perth Amboy Perthshire Related Content Daily Word Quiz: clairvoyant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language