Translation
powered by 
English - English (Wordnet) dictionary
(also found in
English - Vietnamese)
headfirst
Adjective
- with the head foremost
- a headfirst plunge down the stairs
- a headlong dive into the pool
- a headfirst plunge down the stairs
Adverb
- with the head foremost
- the runner slid headlong into third base
- the runner slid headlong into third base