Be said falsely to be prejudiced (6)
I believe the answer is:
biased
'be prejudiced' is the definition.
(I've seen this before)
'be said falsely' is the wordplay.
'falsely' is an anagram indicator.
'be'+'said'='besaid'
'besaid' with letters rearranged gives 'BIASED'.
'to' acts as a link.
(Other definitions for biased that I've seen before include "Prejudiced or partisan" , "favouring a particular idea" , "Having prejudice" , "Not impartial" , "Having favourite" .)