/ Dictionary / Index A actinolite: Meaning and Definition of Find definitions for: ac•tin•o•lite Pronunciation: (ak-tin'l-īt", ak'tu-nl-), [key] — n. Mineral. a variety of amphibole, occurring in greenish bladed crystals or in masses. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: actinolite (Thesaurus) actinoid actinology Related Content Daily Word Quiz: sinister Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language