smoke screen or smoke·screen (smōkskrēn)
n.
► A mass of dense artificial smoke used to conceal military areas or operations from an enemy.
► An action or statement used to conceal actual plans or intentions.

[TahlilGaran] American Dictionary ▲

smoke screen
n. phr. A camouflage; a veil; something used to cover or hide something.
June hides her commercial interests behind a smoke screen of religious piety.

[TahlilGaran] English Idioms Dictionary ▲