What associates say is true - they've imprisoned writer (8)
I believe the answer is:
essayist
'writer' is the definition.
(I know that essayist is a type of writer)
'what associates say is true they've imprisoned' is the wordplay.
'ESSAYIST' is hidden within the letters.
But, I am uncertain how the hidden word is indicated.
Can you help me to learn more?
(Other definitions for essayist that I've seen before include "Lamb, perhaps" , "Writer of pieces on various subjects" , "Writer of little prose pieces" , "Writer of shorter pieces" , "The venturer" .)