Assertion from church after nun briefly enters pub (10)
I believe the answer is:
insistence
'assertion' is the definition.
(thesaurus)
'from church after nun briefly enters pub' is the wordplay.
I cannot really understand how this works, but
'from' could be 'in' (I've seen this in other clues) and 'in' is found within the answer.
'church' could be 'ce' (Church of England) and 'ce' is found in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for insistence that I've seen before include "Demand" , "Stress" , "Strictly speaking" , "Imperativeness" , "Urgency" .)