New exam to include end of term average (6)
I believe the answer is:
normal
'average' is the definition.
('normal' can be a synonym of 'average')
'new exam to include end of term' is the wordplay.
'new' becomes 'n'.
'exam' becomes 'oral' (oral exam is a kind of exam).
'to include' is an insertion indicator.
'end of' indicates one should take the final letters.
The last letter of 'term' is 'm'.
'oral' going around 'm' is 'ormal'.
'n'+'ormal'='NORMAL'
(Other definitions for normal that I've seen before include "Average or ordinary" , "'Standard, conventional (6)'" , "Conforming to a standard" , "Ordinary, not extraordinary" , "it's what you'd expect" .)