Meaning of “wee” - Learner’s Dictionary

wee

noun [ no plural ] uk us /wiː/ mainly UK informal

If someone has a wee, they urinate:

to have a wee
I need a wee.
wee verb [ I ] (present participle weeing, past tense and past participle weed)

(Definition of “wee noun” from the Cambridge Learner’s Dictionary © Cambridge University Press)