/ Dictionary / Index A adverb clause: Meaning and Definition of Find definitions for: ad'verb clause" Pronunciation: [key] — Gram. Gram. a subordinate clause that functions as an adverb within a main clause. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. adverb adverbial Related Content Daily Word Quiz: spectral Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language