Binding (8)
'binding' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for ligature that I've seen before include "Cord used by surgeons" , "Surgical, musical, tie" , "Character combining two letters" , "link" , "Musical slur" .)
'binding' is the definition.
(thesaurus)
This is all the clue.
(Other definitions for hard-and-fast that I've seen before include "Not able to be changed" , "Rigidly applied" .)