The English word SWAMI comes from Hindi swāmī, meaning "lord, prince, master," a term of respect. The Hindi word in turn comes from Sanskrit svāmin. The word in English is most often used used now to refer to a religious teacher, but it can also be used to refer to a god in the form of an idol, and likewise to jewelry that is decorated with divine figures.
You can see the title regularly used for Swami Vivekananda, for example, a Hindu monk and disciple of Ramakrishna. Swami Vivekenanda played a key role in transmitting both Vedanta and Yoga to Western audiences, as in his famous speech given at the Parliament of the World's Religions in Chicago in 1893 and in lecture tours conducted in the United States, England and France. You can read more in the article about Swami Vivekananda's life at Wikipedia, and also in this article on the Teachings and Philosophy of Swami Vivekananda.