Feature securing a series of links (5)
I believe the answer is:
chain
'series of links' is the definition.
(I've seen this before)
'feature securing a' is the wordplay.
'feature' becomes 'chin' (chin is a kind of feature).
'securing' indicates putting letters inside.
'chin' placed around 'a' is 'CHAIN'.
(Other definitions for chain that I've seen before include "Connected sequence" , "Series of links; sixty six feet" , "Mountain range" , "Set of links" , "distance for a run?" .)