/ Thesaurus / H Synonyms of heat lightning Find synonyms for: Noun1. heat lightning, lightningusage: bright flashes of light near the horizon without thunder (especially on hot evenings); usually attributed to distant lightning that is reflected by cloudsWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: philanthropy Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language