To urinate or deficate in an area other than a toilet.
Such as a dog using the bathroom in your bed. A child in his diaper. An angry man in front of patrons in a restarant or bar as an act of drunkiness.
Tim, in a drunkin mind state, told the bartender, "Fuck You!" after he refused to serve him another drink, pulled out his penis and began to freecalate. He was later beaten and drug out of the establishment by bouncers.