/ Dictionary / Index M mineraloid: Meaning and Definition of Find definitions for: min•er•al•oid Pronunciation: (min'ur-u-loid"), [key] — n. a mineral substance that does not have a definite chemical formula or crystal form. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. mineralogy mineral oil Related Content Daily Word Quiz: abominable Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language