headlong

headlong
adv, adj [attrib 作定语]
1 with the head first 头在前（的）: fall headlong 倒栽葱.
2 in a hasty and rash way 迅急莽撞（的）
    rush headlong into danger 不顾一切地迎著危险冲上去.

牛津英汉双解词典