Its an adjective to describe how stupid or retarded someone is acting. it can also be used as a form of pet name or nickname toward another person. The word bumbaclott origantes from the Country of Guyana in South America, who speak broken english. Its a form of a guyanese slang
"You fucken bumbaclott, that's not how ya scunt hole play that gam"
Sometimes in life there are rogue bumbaclaat's and lone pussy bwoys but very often they congregate into larger groups and form societies and institutions. They make their own rules and then try and impose them on others or try to take your wealth and heath for themselves. Bumbacultists often perform strange rituals and have even been known to steal mansherb. Watch out for Bumbacults!
Johnny used to be a good man until he joined that Bumbacult, now he is a vampire like those other filthy bumbacultists.