When an individual participates in a dating site hookup only to discover that the other individual is substantially larger than you were initially led to believe.
When a “bigger” gal only takes pictures from the neck or chest up to appear skinny but in person she’s totally a bigger gal.
Danny: what’s up with you and that girl you met on tinder bro?
Nick: Oh her? Nah man she fatfished me. Totally got me dude. Nothing like her picture.
Danny: Damn bro that’s crazy! Shit...
Similar to being catfished or fatfished, bratfished means the person you went on a date with was not immediately up front with the fact that they have children.
When you match with a girl on Tinder thinking she's fit but then you scroll through to her last picture, only to see she's slightly on the bigger side.
Jim: "Guys, I got a new match on Tinder"
Jim: *Scrolls through new matches Tinder profile*
Jim: "FUCK! I've been Fatfished