Reserve an enclosure after a fashion (7)
I believe the answer is:
modesty
'reserve' is the definition.
(I know that reserve can be written as modesty)
'an enclosure after a fashion' is the wordplay.
I cannot really understand how this works, but
'enclosure' could be 'sty' (sty is a kind of enclosure) and 'sty' is found in the answer.
'fashion' could be 'mode' (synonyms) and 'mode' is present in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for modesty that I've seen before include "Decorum, shyness" , "lack of vanity" , "Way to get disorderly house under" , "Reserve" , "Unassuming character" .)