Breadcrumb Home > Dictionary > Index H headfirst: Meaning and Definition of Find definitions for: head•first Pronunciation: (hed'fûrst'), [key] — adv. with the head in front or bent forward; headforemost: He dived headfirst into the sea. rashly; precipitately. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: headfirst (Thesaurus) header bond headfish ✖ Related Content Daily Word Quiz: legerdemain Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language