Offending jewellery on sovereign (6)
I believe the answer is:
erring
'offending' is the definition.
Although both the answer and definition are present participle verbs, I can't see how they can define each other.
'jewellery on sovereign' is the wordplay.
'jewellery' becomes 'ring' (ring is a kind of jewellery).
'on' says to put letters next to each other.
'sovereign' becomes 'er' (Abbreviation for Elizabeth Regina).
'ring' after 'er' is 'ERRING'.
Can you help me to learn more?
(Other definitions for erring that I've seen before include "Being incorrect" , "Making 7 down" , "Making a mistake" , "Sinful" , "taking wrong direction" .)