Breadcrumb Home > Dictionary > Index I ignimbrite: Meaning and Definition of Find definitions for: ig•nim•brite Pronunciation: (ig'nim-brīt"), [key] — n. Petrol. a fine-grained volcanic rock consisting mainly of welded shards of feldspar and quartz. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. ignescent ignis fatuus ✖ Related Content Daily Word Quiz: deracinate Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language