Short book, rather dull (4)
I believe the answer is:
matt
This clue might be a double definition.
'short book' is the first definition.
'matt' can be an answer for 'book' (I've seen this before). I'm not certain of the 'short' bit.
'rather dull' is the second definition.
(as opposed to glossy)
Can you help me to learn more?
(Other definitions for matt that I've seen before include "- Lucas (Little Britain)" , "Non-gloss" , "Not glossy" , "Dull, lustreless" , "Lacking a shine" .)