Source : Webster's Revised Unabridged Dictionary (1913)

Austereness \Aus*tere"ness\, n.
   1. Harshness or astringent sourness to the taste; acerbity.
      --Johnson.

   2. Severity; strictness; austerity. --Shak.

Source : WordNet®

austereness
     n : extreme plainness [syn: {severeness}]