The Collaborative International Dictionary of English v.0.48:

Obdure \Ob*dure"\ ([o^]b*d[=u]r"), v. t.
   To harden. [Obs.] --Milton.
   [1913 Webster] Obdure

The Collaborative International Dictionary of English v.0.48:

Obdure \Ob*dure"\ ([o^]b*d[=u]r"), Obdured \Ob*dured"\
   ([o^]b*d[=u]r"), a.
   Obdurate; hard. [Obs.]
   [1913 Webster]

         This saw his hapless foes, but stood obdured. --Milton.
   [1913 Webster] Obdureness