Prophets accepting nationalist's contemptuous remarks (6)
I believe the answer is:
sneers
'contemptuous remarks' is the definition.
(sneer can mean a contemptuous comment)
'prophets accepting nationalist's' is the wordplay.
'prophets' becomes 'seers' (both can mean people who see the future).
'accepting' is an insertion indicator.
'nationalist' becomes 'N' (abbreviation in politics).
'seers' placed around 'n' is 'SNEERS'.
(Other definitions for sneers that I've seen before include "Contemptuous or scornful remarks" , "Expresses cynical contempt" , "Smiles contemptuously" , "Shows contempt by scornful expression" , "Makes scornful remark, derides" .)