obtund

Meanwhile, The Concise Oxford Dictionary says to obtund is "to blunt or deaden".

In the same way, the obtunding of the nerve cells in the cortex by anaesthetics or of the conducting nerve apparatus on the way to the brain by local anaesthesia, will have a like effect.

In men of genius the moral sense is sometimes obtunded, if not altogether absent.

Often at his desk there, his mind became strangely obtunded and he babbled vapidly; his big face pinched up till it seemed lean and grey, and he pitched forward, face down, upon the desk.

Daily contact with vice obtunds their first abhorrence of it.