An insult used by stoners...Combines "poom" (dick, twat, idiot etc) and "Breh" (Shortened from "brehithwin" - carribean word for brother)
And so creates "poombreh" meaning dickhead, fucker, prick etc, but not as vicious refering it to friends etc.
"he's a poombreh"
Smith says- "That cunt justnicked my lighter!"
Jones replies- "poombreh"