/ Dictionary / Index A anorthoclase: Meaning and Definition of Find definitions for: an•or•tho•clase Pronunciation: (an-ôr'thu-klās", -klāz"), [key] — n. Mineral. a variety of microcline, rich in sodium and sometimes having a play of color: sometimes considered a variety of orthoclase. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. anorthite anorthosite Related Content Daily Word Quiz: fervor Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language