A swami (Sanskrit: स्वामी 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 meaning of the Sanskrit root of the word "Swami" is "one who is one with his Self" ('Swa' stands for self) 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 Bengali, the word (pronounced [ˈʃami]), while carrying its original meaning, has a dual meaning of "husband". The word also means " husband" in Malay, where it is spelled "Suami".
Swami also means husband in Khmer and Odiya.