名词

1. 秘密的;隐藏的;暗中的
Covert activities or situations are secret or hidden.

1. a covering that serves to conceal or shelter something

e.g. a screen of trees afforded privacy
under cover of darkness
the brush provided a covert for game
the simplest concealment is to match perfectly the color of the background

Synonym: screencoverconcealment

2. a flock of coots