Flimflam

Definition: (from dictionary.com)

-noun
1. a trick or deception, especially a swindle or confidence game involving skillful persuasion or clever manipulation of the victim

2. a piece of nonsense; twaddle; bosh
-verb (used with object)
3. to trick, deceive, swindle, or cheat

Examples:
"The scam artist flimflammed me into paying full price for a fake diamond bracelet."
"Instead of using the traditional 'trick or treat' greeting this Halloween, amaze your friends with your intelligence by saying, 'flimflam or treat!'"

Origin: (from etymonline.com)
"1530s, a contemptuous echoic construction, perhaps connected to some unrecorded dialectal word from Scandinavian (cf. Old Norse flim 'a lampoon'). From 1650s as a verb."

Awkwardness rating: 7

I would never flimflam you. These are all genuine diamonds! (bridalsjewelrytips.blogspot.com)