ligament vs ligature

ligament and ligature both are nouns.

Word	Noun	Adjective	Verb	Adverb
ligament	Yes	No	No	No
ligature	Yes	No	No	No

As nouns, ligature is a hyponym of ligament; that is, ligature is a word with a more specific, narrower meaning than ligament:

Other hyponyms of ligament include binder, chain, wire.

ligament (noun)	ligature (noun)
any connection or unifying bond	the act of tying or binding things together
a sheet or band of tough fibrous tissue connecting bones or cartilages or supporting muscles or organs	something used to tie or bind
	thread used by surgeons to bind a vessel (as to constrict the flow of blood)
	a metal band used to attach a reed to the mouthpiece of a clarinet or saxophone
	(music) a group of notes connected by a slur
	character consisting of two or more letters combined into one