ascetic

(noun) someone who practices self denial as a spiritual discipline. Synonyms: abstainer.

(adj) pertaining to or characteristic of an ascetic or the practice of rigorous self-discipline. Synonyms: ascetical. Example: "Ascetic practices."

(adj) practicing great self-denial. Synonyms: ascetical, austere, spartan. Examples: "Be systematically ascetic...do...something for no other reason than that you would rather not do it"- william james." "A desert nomad's austere life." "A spartan diet." "A spartan existence."