Dickens character uncultured after receiving introduction to Gradgrind (5)
I believe the answer is:
rudge
'dickens character' is the definition.
(character in Barnaby Rudge by Charles Dickens)
'uncultured after receiving introduction to gradgrind' is the wordplay.
'uncultured' becomes 'rude'.
'after receiving' means one lot of letters goes inside another.
'introduction to' indicates taking the first letters.
The first letter of 'gradgrind' is 'g'.
'rude' going around 'g' is 'RUDGE'.
(Other definitions for rudge that I've seen before include "Dickensian character" , "Dickensian halfwit" , "'Barnaby - - ' by Charles Dickens" , "Dickens character" , "Dickens novel 'Barnaby .....'" .)