Any woman, of legal age, that by virtue of her less than impressive looks, warrants the use of a Brown Paper Bag when taking her out in public, or in times of close intimate relations.
WOW, I haven't seen Cheryl since high school, and I see she has turned into a perfect BPB. UGH, she's got a face that could stop a clock!
Sarah: Okay Jim, I'm getting on the bus. See you in three years!
Jim: (thinking) Oh no, now I have to get up and I have a BPB! I will have to use the Uptuck method...