Small curl cut back (6)
I believe the answer is:
scrimp
'cut back' is the definition.
(cut back on spending)
'small curl' is the wordplay.
'small' becomes 's' (abbreviation - e.g. clothes size).
'curl' becomes 'crimp' (crimp is a kind of curl).
's'+'crimp'='SCRIMP'
(Other definitions for scrimp that I've seen before include "Be economical, mean, with" , "Be thrifty and parsimonious" , "Economise, be thrifty" , "Skimp, stint" , "Be economical and sparing" .)