Uninteresting house smell (2-3)
I believe the answer is:
ho-hum
'uninteresting' is the definition.
('ho-hum' can be similar in meaning to 'uninteresting')
'house smell' is the wordplay.
'house' becomes 'ho' (abbreviation for house).
'smell' becomes 'hum' (I have seen 'Unpleasant smell ' mean 'hum' so perhaps 'smell' could also mean 'hum').
'ho'+'hum'='HO-HUM'
(Other definitions for ho-hum that I've seen before include "Ah well!" , "Exclamation of boredom and lack of interest" , "Interjection" , "Exclamation to express resignation or boredom" , "Routine" .)