Definition from Wiktionary, the free dictionary
Alternative forms 
gimmick (plural gimmicks)
- A trick or device used to reach some end.
- The box had a gimmick to make the coin appear to vanish.
- April 19 2002, Scott Tobias, AV Club Fightville
- Epperlein and Tucker focus on two featherweight hopefuls: Dustin Poirier, a formidable contender who’s looking to parlay a history of schoolyard violence and street-fighting into a potential career, and Albert Stainback, a more thoughtful yet more erratic and undisciplined fighter whose chief gimmick is entering the ring wearing a hat like the one Malcolm McDowell wore in A Clockwork Orange.
- A clever ploy or strategy.
- The contest was a gimmick to get people to sign up for their mailing list.
Derived terms 
trick or a device
clever ploy or strategy
- To rig or set up with a trick or device.
- The magician's box was gimmicked with a wire that made it appear to open on its own.