From Latin 'ligare' (to bind) — literally 'that which binds,' describing tissue holding bones together at joints.
A short band of tough, flexible connective tissue that connects two bones or cartilages or holds together a joint.
From Latin 'ligāmentum' (a band, a tie, a bandage, a binding), from 'ligāre' (to bind, to tie, to fasten, to connect), from Proto-Indo-European *leyǵ- (to bind, to tie). The PIE root *leyǵ- generated one of the most productive clusters in legal, medical, and religious Latin. 'Ligāre' directly produced 'ligature' (a binding, a tie in music or surgery), 'ally' (to bind oneself to another — from Latin 'alligāre'), 'obligate' (to bind against or toward — from 'ob-' + 'ligāre'), 'religion' (one interpretation derives it from 're-' + 'ligāre,' to bind back to the divine — though Cicero preferred
The Latin root 'ligāre' (to bind) connects ligaments to some surprising relatives. 'Religion' may derive from 'religāre' (to bind back, to bind fast) — Lactantius argued that religion 'binds' humans to God. 'League' (an alliance) comes from 'ligāre' through Italian 'lega.' Even 'rally' and 'rely' trace back to 'ligāre' through Old French 're-' + 'alier' (to ally, to bind together