adj. 1) A person whose face must be coverd by a brown paper bag in order to enter any form of relationship with them; 2) An unattractive partner.
"As I'm single right now, I just don't see myself dating a brownbagger any time soon."
"Dude, you are dating such a brownbagger."
"Damn, that Chick's a Stunner, check out that Body!"
"Maybe you should turn her around, check out that face."
"Oh Sh%t, She is such a Brownbagger!"