umbrella

n.

1. (雨)伞
   • Umbrella and raincoats are what people need in rainy days.
     伞和雨衣都是下雨天人们要用的。
2. 起保护作用的力量[势力]
   • They operated under the umbrella of the police.
     他们在警方的掩护下采取了行动。