Regularly buys lead secondhand (4)
I believe the answer is:
used
'secondhand' is the definition.
('used' can be a synonym of 'secondhand')
'regularly buys lead' is the wordplay.
'regularly' indicates alternate letters (regularly take one letter, leave next etc.).
'buys'+'lead'='buyslead'
The alternate letters of 'buyslead' are 'USED'.
(Other definitions for used that I've seen before include "Sued, having been employed" , "Manipulated American editor" , "Previously owned by another" , "Not fresh" , "Worn" .)