Old novel upset war poet (4)
I believe the answer is:
owen
'war poet' is the definition.
'owen' can be an answer for 'poet' (I've seen this before). I am unsure of the 'war' bit.
'old novel upset' is the wordplay.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'novel' becomes 'new' (synonyms).
'upset' says the letters should be written backwards.
'new' written backwards gives 'wen'.
'o'+'wen'='OWEN'
Can you help me to learn more?
(Other definitions for owen that I've seen before include "Clive --, English actor" , "Welsh industrialist and social reformer, founder of cooperative communities, d. 1858" , "Welsh boy's name" , "English war poet, killed 1918" , "Wilfred -, English poet killed in World War One" .)