Grand Dickensian character showing resentment (6)
I believe the answer is:
grudge
'resentment' is the definition.
(I know that grudge is a type of resentment)
'grand dickensian character' is the wordplay.
'grand' becomes 'g' (G is short for grand as in a thousand).
'dickensian character' becomes 'Rudge' (from Charles Dickens' Barnaby Rudge).
'g'+'rudge'='GRUDGE'
'showing' is the link.
(Other definitions for grudge that I've seen before include "Active resentment" , "Resent having to give or acknowledge something" , "A feeling of resentment as at other's success" , "Persistent feeling of resentment" , "Resentment, animosity" .)