The extent of an award (6)
I believe the answer is:
degree
I believe this clue is a double definition.
'the extent' is the first definition.
(I've seen this before)
'an award' is the second definition.
(degree is a kind of award)
'of' is the link.
(Other definitions for degree that I've seen before include "Not much of a turn" , "Further education award - extent" , "Award conferred by a college or university" , "Measure for angle and temperature" , "'Grade, step or award (6)'" .)