Meaning of double-dealing

(adj) marked by deliberate deceptiveness especially by pretending one set of feelings and acting under the influence of another; "she was a deceitful scheming little thing"- Israel Zangwill; "a double-dealing double agent"; "a double-faced infernal traitor and schemer"- W.M.Thackeray

(noun) acting in bad faith; deception by pretending to entertain one set of intentions while acting under the influence of another