Breadcrumb Home > Thesaurus > H Synonyms of headfirst Find synonyms for: Adjective 1. headfirst, headlong, forward (vs. backward) usage: with the head foremost; "a headfirst plunge down the stairs"; "a headlong dive into the pool" Adverb 1. headlong, headfirst usage: with the head foremost; "the runner slid headlong into third base" WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved.Definition and meaning of headfirst (Dictionary) TrendingHere are the facts and trivia that people are buzzing about. Jewish Holidays, 2010-2030 (A.M. 5770-5791) Western Christian Holidays, 2010-2030 12 Steps to a New Year New Year's Resolution to Slim Down? Martin Luther King Speeches Books of the Bible: Old Testament Books in Order ✖ Related Content Daily Word Quiz: nonpareil Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language