A swami (Sanskrit: svāmī [sʋaːmiː]) sometimes abbreviated “sw.” is an ascetic or yogi who has been initiated into the religious monastic order founded by some religious teacher. It is believed to be originally used for the ones who were initiated into to the Advaita Vedanta movement started by Adi Shankara. The usage of this word is not just for a yogi but also used for a religious guru, with or without disciples.
The Oxford English Dictionary gives the etymology as:
Hindi svāmī master, lord, prince, used by Hindus as a term of respectful address, < Sanskrit svāmin in same senses, also the idol or temple of a god.
In the Bengali language, the word (pronounced [ˈʃami]), while carrying its original meaning, has a dual meaning of “husband”. The word also means “husband” in the Malay language, where it is spelled “Suami”. Swami also means husband in the Khmer language.