The noun device has 5 senses (first 3 from tagged texts)
1. (38) device -- (an instrumentality invented for a particular purpose; "the device is small enough to wear on your wrist"; "a device intended to conserve water")
2. (2) device -- (something in an artistic work designed to achieve a particular effect)
3. (2) device, gimmick, twist -- (any clever maneuver; "he would stoop to any device to win a point"; "it was a great sales gimmick"; "a cheap promotions gimmick for greedy businessmen")
4. device -- (any ornamental pattern or design (as in embroidery))
5. device -- (an emblematic design (especially in heraldry); "he was recognized by the device on his shield")