Source : Webster's Revised Unabridged Dictionary (1913)

Insuetude \In"sue*tude\, n. [L. insuetudo, from insuetus
   unaccustomed; pref. in- not + suetus, p. p. of suescere to be
   accustomed.]
   The state or quality of being unaccustomed; absence of use or
   habit.

         Absurdities are great or small in proportion to custom
         or insuetude.                            --Landor.