Adopt evacuee at last with partner (7)
I believe the answer is:
espouse
'adopt evacuee' is the definition.
'espouse' can be an answer for 'adopt' (synonyms). I am unsure of the 'evacuee' bit.
'at last with partner' is the wordplay.
'at' means one lot of letters go next to another.
'last with' becomes 'e' (I can't explain this - if you can you should give a lot more credence to this answer).
'partner' becomes 'spouse' (synonyms).
'e'+'spouse' is 'ESPOUSE'.
Can you help me to learn more?
(Other definitions for espouse that I've seen before include "See opus (anag)" , "Give support to - see soup (anag)" , "See opus to support a cause" , "Follow and promote a cause" , "Embrace" .)