Bond with gun breaking rule, I suspect (8)
I believe the answer is:
ligature
'bond' is the definition.
(I know that ligature is a type of ligament)
'gun breaking rule i suspect' is the wordplay.
'gun' becomes 'gat' (US informal term for a gun).
'breaking' is an insertion indicator.
'suspect' indicates anagramming the letters (a suspicious or unusual spelling).
'rule'+'i'='rulei'
'rulei' anagrammed gives 'liure'.
'gat' inserted inside 'liure' is 'LIGATURE'.
'with' is the link.
(Other definitions for ligature that I've seen before include "Musical slur" , "Bond" , "Binding used for strangulation" , "Thread for sealing blood vessels" , "Bandage, binding" .)