Annuls, being concerned with rings (7)
I believe the answer is:
repeals
'annuls' is the definition.
(I know this)
'concerned with rings' is the wordplay.
'concerned with' becomes 're' ('re' means regarding or about).
'rings' becomes 'peals' ('peal' can be a synonym of 'ring').
're'+'peals'='REPEALS'
'being' acts as a link.
(Other definitions for repeals that I've seen before include "Annuls an act" , "Sets aside" .)