Nouns

(n)coverta flock of coots
(n)screen, cover, covert, concealmenta covering that serves to conceal or shelter something“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”

Adjectives

(a)covertsecret or hidden; not openly practiced or engaged in or shown or avowed“covert actions by the CIA”, “covert funding for the rebels”
(s)covert(of a wife) being under the protection of her husband“a woman covert”