"The action of blunting or dulling; the condition of being blunted or dulled; (now, Medicine ) = obtundation", Early 17th cent. From Middle French, French obtusion action of blunting or dulling, dullness of mind from post-classical Latin obtusion-, obtusio action of blunting or dulling, condition of being blunted or dulled (Vetus Latina) from classical Latin obtūs-, past participial stem of obtundere + -iō.[obtusion etymology, obtusion origin, 英语词源]