Delta's settlement severely criticised (6)
I believe the answer is:
slated
'severely criticised' is the definition.
(slate can mean to criticise severely)
'delta's settlement' is the wordplay.
'settlement' indicates an anagram.
'deltas' with letters rearranged gives 'SLATED'.
(Other definitions for slated that I've seen before include "censured" , "Tore to shreds" , "Berated with roof tiles?" , "Severely criticised - put on a list" , "Torn to pieces" .)