Threatening apparition swinging moneybag (8)
I believe the answer is:
bogeyman
'threatening apparition' is the definition.
'swinging moneybag' is the wordplay.
'swinging' indicates anagramming the letters.
'moneybag' anagrammed gives 'BOGEYMAN'.
(Other definitions for bogeyman that I've seen before include "Imaginary male who frightens children" , "Imaginary spirit who frightens children" , "Scary personification?" , "Dreadful being invoked to scare children" , "Jinx" .)