de·ceive / diˈsēv/ • v. [tr.] (of a person) cause (someone) to believe something that is not true, typically in order to gain some personal advantage: I didn't intend to deceive people into thinking it was French champagne. ∎ (of a thing) give a mistaken impression: [intr.] everything about him was intended to deceive. ∎ (deceive oneself) fail to admit to oneself that something is true. ∎ be sexually unfaithful to (one's regular partner).DERIVATIVES: de·ceiv·a·ble adj.de·ceiv·er n.