/ Dictionary / Index L lava: Meaning and Definition of Find definitions for: la•va Pronunciation: (lä'vu, lav'u), [key] — n. the molten, fluid rock that issues from a volcano or volcanic vent. the rock formed when this solidifies, occurring in many varieties differing greatly in structure and constitution. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: lava (Thesaurus) lav lavabo Related Content Daily Word Quiz: arboreal Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language