Having diahrrea or the action of urinating and passing a bowel movement at the same time.
Gretta: "I have to go the bathroom real bad!"
Marla: "Is it #1 or #2?"
Gretta: "Its worse! I feel a #3 comin' on!"
by gretta March 21, 2005
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Restroom term for diarrhea. If number one is urinate and number two is defecate than number 3 is both at the same time.

Pissing out your butt.

Hershey squirts.
I had number 3 all morning after a night of drinking draft beer!
by Max Pontiac December 20, 2006
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Comes from the childrens nursery rhyme:

Number 1, tickle my bum
Number 2, do a big poo
Number 3, go for a wee
by Kellygirl February 12, 2012
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Rhyming slang for doing a pee or wee (urinate)

In the same way number 2 is rhyming slang for poo.
Had too much to drink, gotta go number 3.
by Jazpur September 4, 2011
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A number 3: a used term, when going to the bathroom. Specifically, going into the bathroom to masturbate.
Henry is taking a number 1, Becky is taking a number 2, and Jack... Is taking a number 3.
by Oweenie Bang Gweenie July 13, 2019
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Suzy was relieved when she finally had her number 3.
by Goofnut January 9, 2022
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