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1.
A name givin to a person with either a large flab of skin under there chin. Or to those with hair that grows only below there chin. The hair is uselly short an has a wirey texure.
(a) Hay, is that guy a Chin Sack? look at all that flabby skin.

(b) Yo Chin Sack, ya shave that stubby beard of yours yet?
by Shane Henderson December 23, 2005
 
2.
Chin sacking is balling your fist up and putting the hollow of your hand on a person’s chin, which resembles a scrotum. If done to a person who doesn’t know what’s going on its pretty funny. (tell them what it means afterward.)
try doing the chin sack on someone.
by JakeD. January 09, 2006