c.1400, (transitive) "to render dead, make dull," used occasionally in English, especially in medical jargon; from Latin obtundere "to blunt, make dull, weaken, exhaust," literally "to beat against" (see obtuse). Related: Obtundation; obtunded.
obtund ob·tund (ŏb-tŭnd')
v. ob·tund·ed, ob·tund·ing, ob·tunds
To dull or blunt, especially sensation or pain.