Church article thus reversing confusion (5)
I believe the answer is:
chaos
'confusion' is the definition.
(I know that chaos is a type of confusion)
'church article thus reversing' is the wordplay.
'church' becomes 'ch' (common abbreviation).
'article' becomes 'a' (English indefinite article).
'thus' becomes 'so' (synonyms).
'reversing' says the letters should be written in reverse.
'so' back-to-front is 'os'.
'ch'+'a'+'os'='CHAOS'
(Other definitions for chaos that I've seen before include "mess" , "upheaval" , "disarray" , "Totally disordered state" , "Total disorder and confusion" .)