Declared a verse outstanding (6)
I believe the answer is:
avowed
'declared' is the definition.
(avowing is a kind of declaring)
'a verse outstanding' is the wordplay.
'verse' becomes 'v'.
'outstanding' becomes 'owed' ('owed' can be a synonym of 'outstanding').
'a'+'v'+'owed'='AVOWED'
(Other definitions for avowed that I've seen before include "Openly asserted" , "Professed" , "Declared" , "Confessed openly" , "Acknowledged" .)