Means the same thing as inappropriate whizzination; When a pet dog or cat urinates in an inappropriate location, such as in a clothes basket or onto a stack of important papers.
Nikkipissed onto some very important documents this morning; it's clear that she had inappropriate pissination.
Person 1: Cant believe she said that last night!
Person 2: You were drunk !!
Person 1 : But is that what was said??!?!?
Person 2 : No I think you Pissinterpretated!!