Monkey in church – little devil (5)
I believe the answer is:
chimp
'monkey' is the definition.
(thesaurus)
'in church aeur little devil' is the wordplay.
'in' is an insertion indicator.
'church' becomes 'ch' (common abbreviation).
'aeur' becomes 'p' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'little' means to remove the last letter (the word is not quite complete).
'devil' becomes 'imp' (devilish creature).
'ch'+'p'='chp'
'imp' with its last letter taken away is 'im'.
'chp' enclosing 'im' is 'CHIMP'.
Can you help me to learn more?
(Other definitions for chimp that I've seen before include "Cheeky primate" , "A great ape (abbr.)" , "Creature" , "Anthropoid ape" , "Ape (colloq.)" .)