austere
adj.
severely simple
a stark interior
Synonym: severe, stark, stern
adj.
of a stern or strict bearing or demeanor; forbidding in aspect
an austere expression|a stern face
Synonym: stern
adj.
practicing great self-denial
Be systematically ascetic...do...something for no other reason than that you would rather not do it|a desert nomad's austere life|a spartan diet|a spartan existence