Decorator (5)
'decorator' is the definition.
(synonyms)
This is the entire clue.
(Other definitions for interior that I've seen before include "Core" , "Situated within" , "Domestic" , "Inland region" , "Inside part" .)
(Other definitions for tiler that I've seen before include "Craftsman" , "Tradesman who covers roofs or bathroom walls with rectangular materials" , "doorkeeper at lodge" , "Roof worker" , "Roof-worker" .)