ligature vs ligament

ligature and ligament both are nouns.

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

As nouns, ligament is a hypernym of ligature; that is, ligament is a word with a broader meaning than ligature:

ligature (noun)	ligament (noun)
the act of tying or binding things together	any connection or unifying bond
something used to tie or bind	a sheet or band of tough fibrous tissue connecting bones or cartilages or supporting muscles or organs
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