Quality in charmer, I think (5)
I believe the answer is:
merit
'quality' is the definition.
(merit is a kind of quality)
'in charmer i think' is the wordplay.
'in' indicates a hidden word.
'MERIT' is hidden in the letters of 'charmer i think'.
(Other definitions for merit that I've seen before include "Advantage" , "of a high order?" , "Excellence, worth" , "Goodness" , "Deserve or warrant" .)