Hate exam, after two low grades (6)
I believe the answer is:
detest
'hate' is the definition.
(to detest is to hate or loathe)
'exam after two low grades' is the wordplay.
I cannot quite understand how this works, but
'exam' could be 'test' (synonyms) and 'test' is found within the answer.
'low grades' could be 'de' (D and E are low academic grades) and 'de' is located in the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for detest that I've seen before include "Having a loathing" , "Greatly hate" , "Find repulsive" , "Cordially dislike and loathe" , "Dislike thoroughly" .)