Synset

a covering that serves to conceal or shelter something
<noun.artifact>   freq. cnt.: 11 freq. cnt.: 9 freq. cnt.: 2

concealment

cover

covert

screen

sample sentences

"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"