Lecture Trevor perhaps holds over (7)
I believe the answer is:
reprove
'lecture' is the definition.
(thesaurus)
'trevor perhaps holds over' is the wordplay.
'holds' says the answer is hidden in the clue.
'over' says the letters should be written in reverse.
'evorper' is hidden within 'trevor perhaps'.
'evorper' backwards is 'REPROVE'.
(Other definitions for reprove that I've seen before include "Chide" , "carpet" , "Admonish" , "tick off" , "Rebuke, censure" .)