It shelters one in retirement (9)
I believe the answer is:
hermitage
'retirement' is the definition.
Although both the answer and definition are singular nouns, I can't understand how one could define the other.
'it shelters one in' is the wordplay.
'it' becomes 'tag' (playground catching game).
'shelters one' becomes 'hermie' (I can't explain this - if you can you should believe this answer much more).
'in' is an insertion indicator.
'tag' placed inside 'hermie' is 'HERMITAGE'.
Can you help me to learn more?
(Other definitions for hermitage that I've seen before include "Recluse's abode" , "Secluded retreat" , "Place of retreat" , "accommodation for one" , "Museum housing collection started by Catherine the Great" .)