Robber putting gear in the ring (7)
I believe the answer is:
brigand
'robber' is the definition.
(I've seen this before)
'gear in the ring' is the wordplay.
'gear' becomes 'rig' (rig is a kind of gear).
'in the' means one lot of letters goes inside another.
'ring' becomes 'band' (synonyms).
'rig' put inside 'band' is 'BRIGAND'.
'putting' is the link.
(Other definitions for brigand that I've seen before include "Bandit" , "Highway robber" , "Marauder" , "thief" , "Robber in wild places" .)