Merit of paper's boss returning to do adequate job (7)
I believe the answer is:
deserve
'merit' is the definition.
(synonyms)
'paper's boss returning to do adequate job' is the wordplay.
'paper's boss' becomes 'ed' (abbreviation for editor).
'returning' shows that the letters should be reversed in order.
'to do adequate job' becomes 'serve' (as in to adequately serve or function as).
'ed' back-to-front is 'de'.
'de'+'serve'='DESERVE'
'of' is the link.
(Other definitions for deserve that I've seen before include "Justify" , "rate" , "Warrant" , "Show one is worthy" , "Be worth" .)