A girl that meets all the right criteria. Basically your type of girl, as in she ticks all the right boxes.

So in essence she is fit for you, or your size.

Usually used when trying to catch a girl's attention, best used by shouting at them, to get full effect.

Made famous in the film Kidulthood by Jay (played by Adam Deacon)
"E-YO MY SIZE!!! MY SIZE!!!" shouting at a female
by ldndon March 24, 2008
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This is the type of prank you pull on someone while they're yawning. When you see someone yawning, you yell out 'My size!', meaning that the size of your dick takes that much space.
'Oh man, I'm pretty tired.
'Yea man, so am I. *yawns*.'
'MY SIZE!'
'Yea, you feel proud of yourself, fuckboy?'
by Daddy 8======D November 5, 2018
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A bitch who has one or more of these traits:
1. Steals all her boyfriend's money
2. Hates everyone, but expects everyone to like her anyways
3. Very stuck up
4. Displeasing to the entire female population (this includes animals) and emits a rancid odor detectable by most
5. Gets her boyfriend way too whipped

Abbreviated: MSB
Alicia and Bethany are my sized bitches. I feel sorry for Ben and Nathan (respectively).

and

I contain no MSB
by Mr. Tap July 13, 2004
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