n. an attendant employed at a beach or pool to protect swimmers from accidents
n. 卫兵, 禁卫军, 救生员
1. The lifeguard watched over the swimming pool to keep everyone safe.
救生员在游泳池旁边监视，以确保每个人的安全。
2. She decided to become a lifeguard because she loves swimming.
她决定成为一名救生员，因为她喜欢游泳。
3. The lifeguard blew his whistle to signal a warning to the swimmers.
救生员吹响哨子，向游泳者发出警告。