To spit hot flame. To make a lyrical line so hard that all of your bros legit can't help themselves but drool and start seizing. The ultimate bar. Something that comes out but never leaves the room. The word "one ear out the other" doesn't exist. It'll change your life.
"Da man dem spit big man cyphe, he be da big man boss man"
"Bro, he legit just cyphed so hard. That shit was too good, we need to find a beat for that."
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!"