The Collaborative International Dictionary
take a piss
Piss \Piss\, n. Urine. [vulgar]
take a piss urinate. [vulgar]
Usage examples of "take a piss".
Trader always said when you first joined you was always sneaking off to take a piss before the shooting started.
Dean returned to the wag, scrambling over the tailgate, after hopping off the side to take a piss.
No grub or liquor and those God-cursed paper houses're like living in a field - a man can't take a piss or pick his nose.