gimmick (Noun) — A drawback or difficulty that is not readily evident. ex. "it sounds good but what's the gimmick?"
gimmick (Noun) — Something unspecified whose name is either forgotten or not known. ex. "she eased the ball-shaped gimmick back into its socket"
gimmick (Noun) — Any clever manoeuvre. ex. "it was a great sales gimmick" ex. "a cheap promotions gimmick for greedy businessmen"