Article on parishioner taxes is in opposition (10)
I believe the answer is:
antithesis
'opposition' is the definition.
(antithesis is a kind of opposition)
'article on parishioner taxes is in' is the wordplay.
'article' becomes 'the' (the definite article in English).
'on parishioner taxes' becomes 'antis' (I am not sure about this - if you are sure you should believe this answer much more).
'in' means one lot of letters goes inside another.
'antis'+'is'='antisis'
'the' put within 'antisis' is 'ANTITHESIS'.
Can you help me to learn more?
(Other definitions for antithesis that I've seen before include "Opposite; contrasting idea" , "Contrast between two things" , "Direct opposite" , "Opposition" , "opposing view" .)