Being British Disorder, if you know someone with horrible teeth, obsessed with tea, and has a cartoonish british accent; they may be afflicted and should seek medical treatment.
"My friend has stage 2 BBD"
"Saw shit dude is it bad?"
"He keeps singing a littlejig about bangers and mash, it's sad."
In the webcomic, Lore Olympus' fandom, the term BBD refers to Big Blue Daddy aka Hades, King of the Underworld. The origin of the terms is uncertain, but one just needs to take a look at Hades to realize he is indeed, a Big Blue Daddy.
Fan 1: Did you read the latest episode? I want that BBD to lay his hands on me!
Fan 2: Fuck yes