Study follows boring old writer (6)
I believe the answer is:
dryden
'old writer' is the definition.
(17th-century poet John Dryden)
'study follows boring' is the wordplay.
'study' becomes 'den' (term for a study or office).
'follows' is a charade indicator (letters next to each other).
'boring' becomes 'dry' (dry can mean dull or boring).
'den' after 'dry' is 'DRYDEN'.
(Other definitions for dryden that I've seen before include "Charles II's Poet Laureate" , "John --, English 17th-cent. poet/dramatist" , "John --, first Poet Laureate" , "17th-century poet" , "Mac Flecknoe was his" .)