A flimflam is a type of scam or con. If you're smart and savvy enough to recognize a flimflam, you won't get cheated out of your money.
When someone plans a complicated scheme for tricking people out of their property or money, it's a flimflam. Many flimflams are some version of a con, or "confidence game," in which the con artist first gains the trust (or "confidence") of the victim, and then swindles money from him. You can also use flimflam as a verb: "He tried to flimflam me out of my entire bank account."