Qualification held by rude Greek (6)
I believe the answer is:
degree
'qualification' is the definition.
(university qualification)
'held by rude greek' is the wordplay.
'held by' says the answer is hidden in the clue.
'DEGREE' is hidden within 'rude greek'.
(Other definitions for degree that I've seen before include "Unit of measurement of angles" , "Further education award - extent" , "Award conferred on a 1 across" , "Unit of measurement of angle" , "displayed by small elevated circle" .)