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fearfully; timidly; nervously; cautiously; gingerly
恐る恐るドアを開けた。
I fearfully opened the door.
子供が恐る恐る犬に手を伸ばした。
The child nervously reached out to the dog.
恐る恐る上司に休暇の相談を持ちかけた。
I nervously brought up the topic of vacation with my boss.