Tight; average (4)
I believe the answer is:
mean
This clue is a double definition.
'tight' is the first definition.
(I know that tight can be written as mean)
'average' is the second definition.
(type of average)
(Other definitions for mean that I've seen before include "Despicable" , "Name for being tight-fisted" , "Intend; not generous" , "Intend; unkind" , "Name for being stingy" .)