Ancient invader (4)
I believe the answer is:
goth
'ancient invader' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for goth that I've seen before include "Youngster clad in black" , "One of Germanic tribe that invaded Roman empire" , "punk style" , "Girl in black perhaps" , "Rock music fan favouring black clothing" .)