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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," from Latin ligare "to bind, to tie" (see ligament). With -able. General sense of "exposed to" (something undesirable) is from 1590s. Incorrect use for "likely" is attested by 1886.