a person who dedicates his or her life to a pursuit of contemplative ideals and practices extreme self-denial or self-mortification for religious reasons.

a person who leads an austerely simple life, esp. one who abstains from the normal pleasures of life or denies himself or herself material satisfaction.

(in the early Christian church) a monk; hermit.

pertaining to asceticism.

rigorously abstinent; austere

an ascetic existence.

exceedingly strict or severe in religious exercises or self-mortification.

adjective

abstaining , abstemious , abstinent , austere , disciplined , puritanical , spartan , strict , anchorite , celibate , drastic , eremite , essene , exacting , fakir , firm , fixed , harsh , hermit , monk , precise , recluse , rigorous , self-denying , self-disciplined , severe , stark , stoic , stylite , unbending , yogi