Ascetic

1. adjective

   pertaining to or characteristic of an ascetic or the practice of rigorous self-discipline

   “ascetic practices”

   Similar: ascetical

2. noun

   someone who practices self denial as a spiritual discipline

   Similar: abstainer

3. 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: ascetical, austere, spartan