形容詞 under cover:

1. conducted with or marked by hidden aims or methods
   同義詞：clandestine, cloak-and-dagger, hole-and-corner, hugger-mugger, hush-hush, secret, surreptitious, undercover, underground

1. The soldiers crept forward under cover of darkness.
   士兵在夜色的掩護下匍匐前進。
2. He kept his invention under cover until it was patented.
   在取得專利權以前，他的發(fā)明一直秘而不宣。
3. Crimes committed under cover of patriotism.
   打著愛國的旗號犯下的罪行。
4. We travelled under cover of darkness.
   我們在夜幕掩護下行進。