Be said to be prejudiced (6)
I believe the answer is:
biased
'prejudiced' is the definition.
(biasing is a kind of prejudicing)
'be said to be' is the wordplay.
'to be' indicates an anagram.
'be'+'said'='besaid'
'besaid' with letters rearranged gives 'BIASED'.
(Other definitions for biased that I've seen before include "not fair" , "Having prejudice" , "Having favourite" , "'One-sided, slanted (6)'" , "Influenced unfairly" .)