Earth to become fine with time (4)
I believe the answer is:
sett
'earth' is the definition.
(both can refer to an animal's underground home)
'fine with time' is the wordplay.
'fine' becomes 'set' (I can't explain this - if you can you should give a lot more credence to this answer).
'with' says to put letters next to each other.
'time' becomes 't' (abbreviation).
'set'+'t'='SETT'
'to become' is the link.
Can you help me to learn more?
(Other definitions for sett that I've seen before include "Retreat" , "Badger's home" , "Badgers' lair" , "paving stone" , "beastly accommodation" .)