One might take this for object that is an oddity (9)
I believe the answer is:
exception
'that is an oddity' is the definition.
(thesaurus)
'one might take this for object' is the wordplay.
'one might take' becomes 'except' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'this for' is a charade indicator (letters next to each other).
'object' becomes 'ion' (ion is a kind of object).
'except'+'ion'='EXCEPTION'
Can you help me to learn more?
(Other definitions for exception that I've seen before include "Something not following a rule" , "Something that does not follow the rule" , "breach of rule" , "Something not conforming to a rule" , "The one that proves the rule" .)