The Collaborative International Dictionary of English v.0.48:

Assuetude \As"sue*tude\, n. [L. assuetudo, fr. assuetus
   accustomed.]
   Accustomedness; habit; habitual use.
   [1913 Webster]

         Assuetude of things hurtful doth make them lose their
         force to hurt.                           --Bacon.
   [1913 Webster]