Usual level or amount (3)
I believe the answer is:
par
I believe this is a double definition.
'usual level' is the first definition.
(I've seen this before)
'amount' is the second definition.
(par is a kind of amount)
(Other definitions for par that I've seen before include "normal amount" , "Standard score for golfers" , "Usual or expected level" , "Rating of strokes required for hole (golf)" , "Standard number of strokes for a golf-hole" .)