Prophet interrupted by new scornful remark (5)
I believe the answer is:
sneer
'scornful remark' is the definition.
(I've seen this before)
'prophet interrupted by new' is the wordplay.
'prophet' becomes 'seer' (I've seen this before).
'interrupted by' is an insertion indicator.
'new' becomes 'n'.
'seer' placed around 'n' is 'SNEER'.
(Other definitions for sneer that I've seen before include "Contemptuous remark" , "Derisive remark" , "Contemptuous look" , "Dig" , "Curl one's lip" .)