Incorrectly be said to be prejudiced (6)
I believe the answer is:
biased
'be prejudiced' is the definition.
(I've seen this before)
'incorrectly be said' is the wordplay.
'incorrectly' is an anagram indicator (I've seen this in other clues).
'be'+'said'='besaid'
'besaid' with letters rearranged gives 'BIASED'.
'to' acts as a link.
(Other definitions for biased that I've seen before include "Having prejudice" , "Prejudiced or influenced in favour or against" , "Having favourite" , "Prejudiced or partisan" , "favouring a particular idea" .)