adv. 1. With the head leading; headfirst: The runner slid headlong into third base. 2. In an impetuous manner; rashly: rushed headlong into an agreement. adj. (hĕdlông′, -lŏng′) 1. Done with the head leading; headfirst: a headlong dive. 2. Impetuous; rash. See Synonyms at impetuous. 3. Archaic Steep; sheer. |
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2022 by HarperCollins Publishers. All rights reserved.