headlong

adverb

1. with the head foremost; headfirst: to plunge headlong into the water.
2. without delay; hastily: to plunge headlong into work.
3. without deliberation; rashly: to rush headlong into battle.

adjective

4. undertaken quickly and suddenly; made precipitately; hasty: a headlong flight.
5. rash; impetuous: a headlong denunciation.
6. done or going with the head foremost: a headlong dive into the pool.

adverb, adjective

1. with the head foremost; headfirst
2. with great haste

adjective

3. archaic (of slopes, etc) very steep; precipitous