Former copper regularly seeks pardons (7)
I believe the answer is:
excuses
'pardons' is the definition.
('excuse' can be a synonym of 'pardon')
'former copper regularly seeks' is the wordplay.
'former' becomes 'ex' (prefix meaning former or onetime).
'copper' becomes 'Cu' (Cu is the chemical symbol for copper).
'regularly' indicates alternate letters (regularly take one letter, leave next etc.).
The alternate letters of 'seeks' are 'ses'.
'ex'+'cu'+'ses'='EXCUSES'
(Other definitions for excuses that I've seen before include "Clears" , "Exempts or condones" , "Lets (someone) off duty" , "Releases from a duty" , "Forgives" .)