adverb taking the 'to' particle, taru-adjective, na-adjective, noun or participle which takes 'suru', intransitive verb
trembling with fear; nervous; filled with trepidation
Describes a state of being extremely nervous or fearful, often in anticipation of something. Commonly used as a する verb or with と (戦々恐々としている). A yojijukugo with a literary feel.
彼は上司に呼ばれて戦々恐々としていた。
He was trembling with fear after being called by his boss.
試験の結果を待つ間、戦々恐々だった。
I was filled with trepidation while waiting for the exam results.