Similar to a cockslap, or getting slapped in the face with a penis. Only difference is that a crank is a way bigger than a normal penis.
"yo that girl on facebook is hot but she's got a dude in her main pic with her"
"who cares I'll crankslap that punk"
Verb, meaning to take a nasty shit
"I don't know how you felt after eating all those buffalo wings the other night, John, but I woke up in the morning and took a wicked spice"