mid-15c., "bound or obliged by law," probably from Anglo-French *liable, from Old French lier "to bind, tie up, fasten, tether; bind by obligation" (12c.), from Latin ligare "to bind, to tie" (from PIE root *leig- "to tie, bind"). With -able. Perhaps from an unattested word in Old French or Medieval Latin. General sense of "exposed to" (something undesirable) is from 1590s. Incorrect use for "likely" is attested by 1850.
"alliance," mid-15c., ligg, from French ligue "confederacy, league" (15c.), from Italian lega, from legare "to tie, to bind," from Latin ligare "to bind" (from PIE root *leig- "to tie, bind"). Originally among nations, subsequently extended to political associations (1846) and sports associations (1879). League of Nations is attested from 1917 (created 1919).
1660s, "bond, link, interdependence between members of a series or group; means of communication," from Latin nexus "that which ties or binds together," past participle of nectere "to bind," from PIE root *ned- "to bind, tie."
before vowels desm-, word-forming element used in scientific compounds and meaning "band, bond, ligament," from Greek desmos "bond, fastening, chain," related to dein "to bind," from PIE root *dē- "to bind."
band of tough tissue binding bones, late 14c., from Latin ligamentum "a band, bandage, tie, ligature," from ligare "to bind, tie," from PIE root *leig- "to tie, bind." Related: Ligamental; ligamentous; ligamentary.
1540s, "to bind, fasten, connect," the literal sense of the Latin word, now obsolete in English; 1660s in the main modern sense of "to put under moral obligation;" a back-formation from obligation, or else from Latin obligatus, past participle of obligare "to bind, bind up, bandage," figuratively "put under obligation" (see oblige). Oblige, with which it has been confused since late 17c., means "to do one a favor." Related: Obligated; obligating.