(adj) marked by deliberate deceptiveness especially by pretending one set of feelings and acting under the influence of another; - Israel Zangwill; ; - W.M.Thackeray, Syn. double-tongued, two-faced, Janus-faced, duplicitous, double-faced, deceitful, double-dealing, Example:she was a deceitful scheming little thing; a double-dealing double agent; a double-faced infernal traitor and schemer
Janus-faced lock, one having duplicate faces so as to go upon a right or a left hand door, the key entering on either side indifferently. Knight. [ 1913 Webster ]