/ Dictionary / Index M microcrystalline: Meaning and Definition of Find definitions for: mi•cro•crys•tal•line Pronunciation: (mī"krō-kris'tl-in, -īn"-), [key] — adj. minutely crystalline; composed of microscopic crystals. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: microcrystalline (Thesaurus) microcrystal microculture 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