Warn about initial ball and chain (6)
I believe the answer is:
albert
'chain' is the definition.
(I've seen this before)
'warn about initial ball' is the wordplay.
'warn' becomes 'alert' (alerting is a kind of warning).
'about' indicates putting letters inside.
'initial' indicates taking the first letters.
The initial letter of 'ball' is 'b'.
'alert' going around 'b' is 'ALBERT'.
'and' is the link.
(Other definitions for albert that I've seen before include "Kind of watch chain" , "Prince of Monaco" , "- - Finney" , "Victim of lion" , "Einstein or Schweitzer?" .)