Post chain's not forged (9)
I believe the answer is:
stanchion
'post' is the definition.
(stanchion is a kind of post)
'chain's not forged' is the wordplay.
'forged' indicates an anagram.
'chains'+'not'='chainsnot'
'chainsnot' is an anagram of 'STANCHION'.
(Other definitions for stanchion that I've seen before include "Upright" , "Vertical post or rod as a support" , "Post or rod used as a support" .)