ablative — ODE

ablative /ˈablətɪv

▸ adjective

1 Grammar denoting a case (especially in Latin) of nouns and pronouns and words in grammatical agreement with them indicating an agent, instrument, or source, expressed by ‘by’, ‘with’, or ‘from’ in English.

2 (of surgical treatment) involving ablation:

all nine patients were treated by ablative surgery.

3 relating to or subject to ablation through melting or evaporation:

the spacecraft's ablative heat shield.

▸ noun Grammar a word in the ablative case.

▪ (the ablative) the ablative case.

– ORIGIN late Middle English: from Old French ablative (feminine of ablatif), Latin ablativus, from ablat- ‘taken away’ (see ablation).