One who, through a combination of skill and conning tactics, is able to coerce card players into senses of false security, then easily defeat them and earn large amounts of money. Also known as card sharp. See wordpool shark/word
I lost $1200 to that card shark. And I thought I had the upper hand...
A door wall is a sliding-glass door or patio door. The term is yet another example of banal Michigan vernacular, where in the residents latch on to company names, trademark names, marketing terms and product names from local companies. The terms become embedded in the local vocabulary and eventually become accepted as actual valid words and phrases. In this case the term comes from Wallside Windows in Taylor, MI (a large window manufacturer), where 'door wall' is their created word for sliding-glass door.
"Bob! John's gonna bring over them doorwalls from Wallsides on Tuesdee afternoon 'round two-thirty. Get 'er done!"