VERB- To relax at home during one's free time, as a fat girl might do on a Saturday night. Often includes watching television, drinking beer, lounging lazily on the couch.
"Are you going out clubbing tonight?" "No, it's been a long week and I'm tired, so I'm just going to fatgirl it."
by Creff von Crinklepants March 14, 2006
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(verb) to impede one's significantly more attractive friends from enjoying themselves because one is obese and unattractive.
Dan: So, how was did your night with Liz last night?

Bob: Eh, it was going good until Katie fatgirled me and made Liz leave.
by GrigShow October 14, 2007
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v. To eat the rest of a bagged snack food by shaking the remaining contents directly into one's mouth.
Do you want anymore of these chips, or can a just fatgirl them?
by Schira October 5, 2007
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A condition or state (term is based on the name of the UK group "Fatboy Slim") wherein:

1) A fat girl eats like a bird in public, thereby suggesting that she is fat NOT because she eats everything in sight, but because she suffers from some kind of thyroidal dysfunction
2) A fat girl has lost weight & yet managed to retain good qualities developed from when she was a fat girl (such as her low-maintenance personality or sense of humor)
Girl 1: You think Maggie really has a thyroid problem? Whenever we get lunch she eats like, half her sandwich and drinks Coke Light..
Girl 2: Yeah, no. The guys left a hidden camera in that classroom that no 1 ever uses & caught her wolfing down 3 Big Macs after school hours.
Girl 1: So she's a run-of-the-mill fatgirl slim..
by catfight12 January 5, 2009
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