1. The thief sidled up to the unsuspecting victim and stole her purse.
小偷悄悄地靠近毫不知情的受害者，偷走了她的钱包。

2. He sidled into the room, hoping no one would notice his late arrival.
他悄悄地侧身走进了房间，希望没人注意到他晚到。