Wailing spirit has been wandering (7)
I believe the answer is:
banshee
'wailing spirit' is the definition.
(I've seen this in another clue)
'has been wandering' is the wordplay.
'wandering' indicates anagramming the letters.
'has'+'been'='hasbeen'
'hasbeen' anagrammed gives 'BANSHEE'.
(Other definitions for banshee that I've seen before include "Howler" , "Wailing woman from Gaelic myth" , "Ominous wailing spirit" , "'Wailing woman, warns of impending death (7)'" , "no one wishes to hear" .)