Spot Dickens character (3)
I believe the answer is:
pip
This clue is a double definition.
'spot' is the first definition.
(both can mean a small amount)
'dickens character' is the second definition.
(I've seen this in another clue)
(Other definitions for pip that I've seen before include "one signals lieutenant" , "Dickens hero" , "Dickensian hero" , "'Seed, of an apple say (3)'" , "Annoyed" .)