i Register
In some senses, pee-pee is marked as slang, colloquial. Watch for register when choosing this word.
noun
Urine.
The penis or vulva; genitalia.
[…]while passing the sponge over the upper part of the little fellow's thighs, the nurse cried out, "O, doctor! be very careful—don't touch his pee-pee—it's very sore;" and upon examining his penis I found it in a state of extreme erection.
A pee-pee for making Wee-Wee.
verb
To urinate.