Diocesan council, say, ignoring a show of consent (5)
I believe the answer is:
synod
'diocesan council' is the definition.
(an assembly of bishops from different dioceses)
'say ignoring a show of consent' is the wordplay.
'ignoring' suggests deleting specific letters.
'show of consent' becomes 'nod' (a nod indicates consent or agreement).
'say' with 'a' removed is 'sy'.
'sy'+'nod'='SYNOD'
(Other definitions for synod that I've seen before include "Church assembly" , "Clerical assembly" , "Assembly of the clergy" , "Council of clergy to discuss policy" , "Ecclesiastical gathering" .)