Though not the oldest, we're in a home (6)
I believe the answer is:
newest
'though not the oldest' is the definition.
I can't tell whether this definition defines the answer.
'we're in a home' is the wordplay.
'we're' becomes 'we' (I can't explain this - if you can you should believe this answer much more).
'in' indicates putting letters inside.
'a home' becomes 'nest' (a bird's home).
'we' going into 'nest' is 'NEWEST'.
Can you help me to learn more?
(Other definitions for newest that I've seen before include "Freshest, most modern" , "Most original" , "Freshest, most recent" , "Superlatively modern" , "Latest novel" .)