He signed the contract precipitately and later realized the terms were unfavorable.

precipitately 是形容词 precipitate 的副词形式，由前缀 pre-（表示“在前”）和词根 -cipit（来自拉丁语 caput，意为“头”）组成，字面意思是“头朝前地”，引申为“仓促地、轻率地”。这个词强调行动前缺乏充分考虑，带有负面含义。