"tending to mislead or give false impression," 1610s, from French deceptif (late 14c.), from Medieval Latin deceptivus, from decept-, past participle stem of Latin decipere "to ensnare, take in, beguile, cheat," from de "from" or pejorative (see de-) + capere "to take," from PIE root *kap- "to grasp."
In this sense in English it superseded deceptious (c. 1600), from French deceptieux, from Medieval Latin deceptiosus, from deceptionem; also deceptory (mid-15c.), from Latin deceptorious. Related: Deceptively; deceptiveness.