The most immaculate castle on meadow with tree house (8)
I believe the answer is:
cleanest
'meadow with tree house' is the definition.
I can't tell whether this defines the answer.
'the most immaculate castle' is the wordplay.
'the most' means to remove the last letter.
'immaculate' becomes 'clean' ('clean' can be similar in meaning to 'immaculate').
'castle' becomes 'nest' (I can't explain this - if you can you should believe this answer much more).
'clean' with its last letter taken away is 'clea'.
'clea'+'nest'='CLEANEST'
'on' is the link.
Can you help me to learn more?
(Other definitions for cleanest that I've seen before include "Most hygienic" , "Most dirt-free" .)