Author of manifesto, I learned, doing a U-turn (5)
I believe the answer is:
eliot
'author' is the definition.
(novelist George Eliot)
'of manifesto i learned doing a u-turn' is the wordplay.
'of' indicates a hidden word.
'doing a u-turn' shows that the letters should be reversed in order.
'toile' is hidden in the letters of 'manifesto i learned'.
'toile' reversed gives 'ELIOT'.
(Other definitions for eliot that I've seen before include "Pseudonymous writer" , "Author of Adam Bede, d.1880" , "thin material rejected" , "Female novelist" , "T S . . . . . wrote ''The Waste Land''" .)