Shank comes from
2 words joined together, creating a sick fetish type act.
When one SHits in his hand and wANKs = SHANK.
Could possibly mean they are homosexual.
Im not just having a wank, Im having a shank!
Hey man, I ran outta lube. Thats ok you can always
shit in your hand
and wank or have a "shank" if you like.