From WordNet (r) 2.0 (August 2003) [wn]:
peeing
n : informal terms for urination; "he took a pee" [syn: pee,
pissing, piss]
From The Collaborative International Dictionary of English v.0.48 [gcide]:
peeing \pee"ing\ (p[=e]"[i^]ng), n.
Urination; -- an informal term; as, he doesn't like peeing
out of doors. [Inform.]
Syn: pee, pissing, urinating.
[WordNet 1.5]