University publishers put in French article - item for jewellers (5)
I believe the answer is:
loupe
'item for jewellers' is the definition.
(magnifying glass used by jewellers)
'university publishers put in french article' is the wordplay.
'university publishers' becomes 'OUP' (Oxford University Press).
'put in' means one lot of letters goes inside another.
'french article' becomes 'le' (definite article in French).
'oup' going into 'le' is 'LOUPE'.
(Other definitions for loupe that I've seen before include "Jeweller's eyepiece" , "Jeweller's magnifying glass" , "instrument in view of fine work" , "Jeweller's eyeglass" .)