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1 definition by Brian E.Nightingale

 
1.
1)To not behave like a child and to not behave like a woman.
2)To know what masculinity is and what testosterone does.
3)To be an adult male in the truest sense of his manhood.
1)Dude is a MOMMAS BOY, dude needs to man up.
2)Dude is on estrogen, dude doesnt know how to man up.
3)Dude does not mess around, you better man up.
by Brian E.Nightingale October 13, 2007