It's very bad in a Portuguese villa (4)
I believe the answer is:
evil
'it's very bad' is the definition.
(I've seen this before)
'in a portuguese villa' is the wordplay.
'in' indicates a hidden word.
'EVIL' is hidden in the letters of 'portuguese villa'.
(Other definitions for evil that I've seen before include "Depravity, wickedness" , "Profoundly malevolent" , "Wicked or immoral" , "Morally objectionable behavior" , "Vile (anag) -- really bad" .)