From Rap Dictionary
Also spelt bombaclat, bum-ba claat, bumba clot, bumbo klaat , but not bombaclaat , which has a different meaning. Patois (Jamaican) expletive, equivalent to "damn", "shit" or "fuck". "Bumbo" refers to "bottom" or "backside", and "clot" to "cloth". "Clot" has also come to mean a used tampon, and the phrase "bloody clot" is sometimes used . Some also take the "clot" to mean "cunt". John Levy claims that "The phrase bumbo klaat is one of the most coarse expressions in Jamaica. If used publicly it is a jailable offense."  In 1981, Wailers member Peter Tosh released Wanted Dread or Alive, featuring the single "Oh Bumbo Klaat" . "What the bum-ba claat like "aye carumba"" -- Method Man and Redman (America's Most) 
It means bloodclot. Represents the near-superstitious disgust that Jamaican men feel about menstruation. Menstruation is the nastiest thing in the world according to most Jamaican men.
It is also used to relieve the spells of evil and gives enormous energy when surrounded by spiritual vampires.Shouting 'Move your bumbo klaat', does the trick.