Low average (4)
I believe the answer is:
mean
This clue is a double definition.
'low' is the first definition.
(thesaurus)
'average' is the second definition.
(type of average)
(Other definitions for mean that I've seen before include "Intend - shabby" , "Nasty" , "Petty" , "Niggardly" , "purpose" .)