Wee, pee, urinate.

Comes from the childrens nursery rhyme:

Number one, tickle my bum

Number two, do a big poo

Number three, go for a wee
Don't drink too much before bed you'll have to go number three in the middle of the night
by Jazpur October 29, 2011
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Rhyming slang for wee or pee (urinate).

Same as 'number two' is rhyming slang for poo.
by StephenSLR August 24, 2011
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I wish toilets accommodated for number three’s as they do for number ones and twos

I need to attend to my number three by changing my tampon
by Dyslexicdefinition January 09, 2020
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