[ab.la.tive] adj (15c): of, relating to, or constituting a grammatical case expressing typically the relations of separation and source and also frequently such relations as cause or instrument -- ablative n
[2]ab.la.tive adj (ca. 1569) 1: of or relating to ablation
2: tending to ablate "~ material on a nose cone" -- ab.la.tive.ly adv