Study poetry? Just the opposite! (8)
I believe the answer is:
converse
'the opposite' is the definition.
(I've seen this before)
'study poetry?' is the wordplay.
'study' becomes 'con' (con can informally mean to study).
'poetry?' becomes 'verse' ('verse' can be a synonym of 'poetry').
'con'+'verse'='CONVERSE'
'just' acts as a link.
(Other definitions for converse that I've seen before include "Opposing" , "Talk together" , "Talk - opposite" , "Quite the opposite!" , "Have a chat, being contrary" .)