Big Fuckin' Dog - when you're tired of classifying you gigantizoid mutt in casual conversion, you can answer with this acronym to reverse the awkwardness of a pretentious ass waiting to lecture you on his/her canine's bloodline. Your mutt/rescue had better be 100+ lbs. 150lbs+ is ideal.
Swear i didn't make this up. Heard in all the time as a kid in Texas in the 80's. (possible tie to bush/biden-ism)
prick: "oooh, what kinda dog is 'he'? "
me: "well, last time i checked he's an aboriginal BFD."
prick: "oooh, right. they are soooo good with kids."