To wee means to urinate. Wee is an informal word used especially by children. He said he wanted to wee. Wee is also a noun. The baby has done a wee in his potty = pee. to pass water from your body - used by or to children = urinate
[ wE ] (adjective.) 15th century. Middle English we, from we, noun, little bit, from Old English w[AE]ge weight; akin to Old English wegan to move, weigh; more at WAY.