Tight pain, variable (6)
I believe the answer is:
stingy
'tight' is the definition.
(I've seen this before)
'pain variable' is the wordplay.
'pain' becomes 'sting' (sting is a kind of pain).
'variable' becomes 'y' (I've seen this in other clues).
'sting'+'y'='STINGY'
(Other definitions for stingy that I've seen before include "Mean, tight" , "Wasps are" , "Zola cocotte; Darlings' dog (Barrie)" , "Mean and grudging" , "Mean, ungenerous" .)