Confusing clergies with a desecration (9)
I believe the answer is:
sacrilege
'desecration' is the definition.
(I know that desecration can be written as sacrilege)
'confusing clergies with a' is the wordplay.
'confusing' indicates anagramming the letters.
'with' is an insertion indicator.
'clergies' is an anagram of 'scrilege'.
'scrilege' placed around 'a' is 'SACRILEGE'.
(Other definitions for sacrilege that I've seen before include "Misuse of something sacred" , "Extreme disrespect for something holy" , "profanity" , "Desecration, profanation" , "Blasphemous behaviour" .)