Takes exam again - returned part of test is erroneous (6)

I believe the answer is:

resits

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'takes exam again' is the definition.
I know nothing about this answer so I cannot judge whether this works.

'returned part of test is erroneous' is the wordplay.
'returned' is a reversal indicator.
'part of' indicates the answer is hidden within the clue.
'stiser' is hidden within 'test is erroneous'.
'stiser' backwards is 'RESITS'.

Can you help me to learn more?

(Other definitions for resits that I've seen before include "Does paper over" , "Takes the examination again" , "Exams taken for a second time" , "takes 15 [EXAM] again" .)

I've seen this clue in The Irish Times.

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