He reviewed his notes feverishly the night before the exam.

feverishly 是副词，由名词 fever（发烧、狂热）加上后缀 -ish（具有...性质的）构成形容词 feverish（狂热的、兴奋的），再加上副词后缀 -ly 构成。feverishly 形容动作时表示"狂热地、极度紧张地"，暗示像发烧时那样高度专注的状态。