Austere

1. adjective

   of a stern or strict bearing or demeanor; forbidding in aspect

   “an austere expression”

   Similar: stern

2. adjective

   practicing great self-denial; - William James

   “Be systematically ascetic...do...something for no other reason than that you would rather not do it”

   Similar: ascetic, ascetical, spartan

3. adjective

   severely simple

   “a stark interior”

   Similar: severe, stark, stern