When you sweat like crazy from your chest after you drink a large amount of coffee and hair grows half a centimeter every time this happens.

A combination of sweat and chest.
"Dude I've got some crazy "sweast" goin' on right now."
by Doctor Ass! April 1, 2010
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Al: Hey, look at that chick jogging down the street. Her sports bra is soaked!!

Ed: Jesus!! She has a bad case of sweasts!!
by Wardo3:16 September 6, 2008
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