School rebuffed pupil’s denial, employing a process for detecting plagiarism (10)
I believe the answer is:
comparison
'process for detecting plagiarism' is the definition.
I can't tell whether this definition defines the answer.
'school rebuffed pupil's denial employing a' is the wordplay.
'school' becomes 'comp' (short for comprehensive).
'rebuffed' says the letters should be written in reverse.
'pupil's denial' becomes 'nosir' (I can't justify this - if you can you should believe this answer much more).
'employing' indicates putting letters inside.
'nosir' reversed gives 'rison'.
'comp'+'rison'='comprison'
'comprison' placed around 'a' is 'COMPARISON'.
Can you help me to learn more?
(Other definitions for comparison that I've seen before include "Assessment of differences" , "Analogy; likeness" , "In contrast" , "Process of identifying differences" , "Similarity" .)