noun

• (Buddhism) A person who has taken specific lay or monastic vows and who is on the road to perfect knowledge; specifically, one who foregoes personal nirvana in order to help others achieve enlightenment.
• (Buddhism) An enlightened being existing in a form of existence beyond the ordinary forms of physical reality understood and acknowledged by scientific thought, resembling the Western notion of angels, but with a wealth of its own nuances and expectations. These include the compassionate working for enlightenment of all sentient beings.