In tree house, are becoming most familiar? (7)
I believe the answer is:
nearest
'most familiar?' is the definition.
Both the definition and answer are superlative adjectives. Maybe there's an association between them I don't understand?
'in tree house are becoming' is the wordplay.
'in' is an insertion indicator.
'tree house' becomes 'nest' (I can't explain this - if you can you should give a lot more credence to this answer).
'becoming' is an anagram indicator.
'are' is an anagram of 'ear'.
'nest' enclosing 'ear' is 'NEAREST'.
Can you help me to learn more?
(Other definitions for nearest that I've seen before include "Closest, being earnest" , "Most intimate" , "most like Scrooge at first" , "Most local" , "touching?" .)