1. 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.
2. a person who leads an austerely simple life, especially one who abstains from the normal pleasures of life or denies himself or herself material satisfaction.
3. (in the early Christian church) a monk; hermit.
[adjective – also ‘ascetical’]
4. pertaining to asceticism.
5. rigorously abstinent; austere.
6. exceedingly strict or severe in religious exercises or self-mortification.