A person who is knowingly deceived, but values the entertainment inherent in the deception enough to continue to be deceived.
Some smart marks like to see a face lose in shoot screwjobs.
by Japanese linguist February 26, 2015
Losers with no lives, who do nothing but surf the internet all day.
That hermit down the block must be a smart mark.
by Plushtar February 17, 2004