Hate being tested, possibly (6)
I believe the answer is:
detest
'hate' is the definition.
(to detest is to hate or loathe)
'tested possibly' is the wordplay.
'possibly' is an anagram indicator.
'tested' with letters rearranged gives 'DETEST'.
'being' acts as a link.
(Other definitions for detest that I've seen before include "can't stand" , "Greatly hate" , "Abominate" , "Despise or loathe" , "Not like" .)