What is the meaning of gimmick?

noun

• A drawback or difficulty that is not readily evident.
  • usage: "it sounds good but what's the catch"
  • synonyms: catch
• Something unspecified whose name is either forgotten or not known.
  • usage: "she eased the ball-shaped doodad back into its socket"; "there may be some great new gizmo around the corner that you will want to use"
  • synonyms: doodad, doohickey, doojigger, gizmo, gismo, gubbins, thingamabob, thingumabob, thingmabob, thingamajig, thingumajig, thingmajig, thingummy, whatchamacallit, whatchamacallum, whatsis, widget
• Any clever maneuver.
  • usage: "he would stoop to any device to win a point"; "it was a great sales gimmick"; "a cheap promotions gimmick for greedy businessmen"
  • synonyms: device, twist