1. Ascetic Sikh order. The Udāsīs revere Gurū Nānak and the Ādi Granth, claiming as their founder Srī Chand, Gurū Nānak's unmarried elder son. They emphasize celibacy (brahmacarya) in contrast to the mainstream Sikh ideal of grahastī, and so perpetuate Nāth principles within Sikhism.
2. Gurū Nānak described the true udāsī or renunciant in Vār Rāmkalī, Ādi Granth, p. 952.
3. In the janam-sākhīs, udāsī refers to the travels of Gurū Nānak, perhaps because during these he assumed the appearance of travelling mendicants.
"Udāsī." The Concise Oxford Dictionary of World Religions. . Encyclopedia.com. (August 18, 2018). http://www.encyclopedia.com/religion/dictionaries-thesauruses-pictures-and-press-releases/udasi
"Udāsī." The Concise Oxford Dictionary of World Religions. . Retrieved August 18, 2018 from Encyclopedia.com: http://www.encyclopedia.com/religion/dictionaries-thesauruses-pictures-and-press-releases/udasi