John, upset about an article in a book (5)
I believe the answer is:
jonah
'book' is the definition.
(I know that Jonah is a book)
'john upset about an article' is the wordplay.
'upset' is an anagram indicator.
'about' indicates putting letters inside.
'an article' becomes 'a' (the indefinite article in English).
'john' anagrammed gives 'jonh'.
'jonh' enclosing 'a' is 'JONAH'.
'in a' acts as a link.
(Other definitions for jonah that I've seen before include "Whalemeat prophet" , "Reluctant prophet" , "Biblical prophet" , "In Old Testament, he was swallowed by a great fish" , "Prophet - bringer of bad luck" .)