Headlong (adverb)

With the head foremost; forward; precipitately; rashly.

Origin:

Middle english hedlong, from hed head + long long.

Examples:

1. He ran headlong towards the danger.
2. She threw herself headlong into the project.
3. He made a headlong dive into the pool.
4. He went headlong into the new business venture.
5. She plunged headlong into the crowd.