Novel about knight, upright type (5)
I believe the answer is:
roman
'upright type' is the definition.
(term for upright type as opposed to italic)
'novel about knight' is the wordplay.
'novel about' becomes 'roma' (I can't justify this - if you can you should believe this answer much more).
'knight' becomes 'N' (chess abbreviation).
'roma'+'n'='ROMAN'
Can you help me to learn more?
(Other definitions for roman that I've seen before include "Polanski" , "Italian person" , "From Italy's capital" , "A novel" , "ancient empire" .)