Old boy poetry has an upside (7)
I believe the answer is:
obverse
'an upside' is the definition.
I can't judge whether this defines the answer.
'old boy poetry' is the wordplay.
'old boy' becomes 'OB' (abbreviation for a private school 'old boy').
'poetry' becomes 'verse' (synonyms).
'ob'+'verse'='OBVERSE'
'has' is the link.
Can you help me to learn more?
(Other definitions for obverse that I've seen before include "Penny may present such a face" , "Side of coin that bears head or principle design" , "Side of coin that bears principal design or head" , "Side of a coin bearing the head" , "Verbose on the opposite side" .)