<p><strong>Adverb</strong></p><ul><li>With the head foremost; headfirst: to plunge headlong into the water.</li><li>Without delay; hastily: to plunge headlong into work.</li><li>Without deliberation; rashly: to rush headlong into battle.</li></ul><p><strong>Adjective</strong></p><ul><li>Undertaken quickly and suddenly; made precipitately; hasty: a headlong flight.</li><li>Rash; impetuous: a headlong denunciation.</li><li>Done or going with the head foremost: a headlong dive into the pool.</li></ul><p><strong>End of Response</strong></p>