Unexciting apartment (4)
I believe the answer is:
flat
This clue is a double definition.
'unexciting' is the first definition.
(I've seen this before)
'apartment' is the second definition.
(synonyms)
(Other definitions for flat that I've seen before include "Dull; set of rooms" , "Lacking interest" , "Level - below the natural note" , "Level; pad" , "Apartment; even" .)