Excuse from Bengali biographer (5)
I believe the answer is:
alibi
'excuse' is the definition.
(excuse given by a suspect in an investigation)
'from bengali biographer' is the wordplay.
'from' indicates a hidden word.
'ALIBI' is hidden in the letters of 'bengali biographer'.
(Other definitions for alibi that I've seen before include "Timely excuse" , "Suspect's excuse" , "Excuse for not doing something" , "Fact of being elsewhere (legal)" , "Defence of being elsewhere at time of crime" .)