Unsuitable home, small apartment (5)
I believe the answer is:
inapt
'unsuitable' is the definition.
(thesaurus)
'home small apartment' is the wordplay.
'home' becomes 'in' ('he's home' can mean 'he's in').
'small apartment' becomes 'apt' (I've seen this in other clues).
'in'+'apt'='INAPT'
(Other definitions for inapt that I've seen before include "Not proper" , "Not fitting" , "Free from deceit" , "Ill-chosen, not suitable" , "Not fit, unsuitable" .)