A common tird in which the poo is skinny however in tact, being excreted in one piece. It reaches the highest threshold at which the tensile strength of the poo does not break. The term originated from areas where the common house skink resides.
"I did a shit today, it was a total buttskink. It must have been at least 30cm long"
To flick a friends buttock in order to cause a stinging pain. This is a skill perfected by using your index finger and middle finger in a fast flicking motion.