con (kŏn) pronunciation Slang. tr.v., conned, con·ning, cons. To swindle (a victim) by first winning his or her confidence; dupe. n. A swindle. adj. Of, relating to, or involving a swindle or fraud: a con artist; a con job.

"to con" = "to deceive, to trick" Usually, a "con" is a very carefully planned deception, where someone pretends to be friendly, nice or helpful. However, from the start, they hope you will trust them, so that they can get something from you.