: of, relating to, or being a grammatical case (see caseentry 1 sense 3a) that typically marks a person, place, or thing from which someone or something else is separated or the source from which someone or something comes, and is also frequently used to indicate the cause of an event or condition or the instrument by which an action is accomplished see also ablative absolute
Middle English ablatif, borrowed from Anglo-French or Latin; Anglo-French ablatif, borrowed from Latin ablātīvus, from ablātus, suppletive past participle of auferre "to carry away, remove" + -īvus-ive — more at ablate