Mean, par (7)
I believe the answer is:
average
I believe this clue is a double definition.
'mean' is the first definition.
(I know that mean can be written as average)
'par' is the second definition.
(I've seen this in another clue)
(Other definitions for average that I've seen before include "Arithmetic mean" , "Normal; mean" , "Mean - ordinary" , "Moderate" , "Normal amount" .)