duppy means a ghost or spirit
Patois: Yuh duppy man
English: You are a ghost
Ghost or spirit of the dead which is feared throughout the Caribbean. Derives from the African religious belief that a man has two souls: one ascends to heaven while the other stays around for a while or permanently. May be harnessed for good or evil through Jamaican witchcraft (obeah).
Patois: Mi nah guh in deh, mi hear seh duppy in deh.
English: I’m not going in there, I heard that ghosts are in there?
(patois) Mi si a duppy last nite
(english) I saw a ghost last night