A friar is and was a member of one of the Catholic Church's dedicated religious brotherhoods that shun material wealth and live among the common people rather than in monasteries. Friars belong to the mendicant orders that continue to this day.
The four mendicant orders of the Middle Ages were the White Friars, the Hermits of St. Augustine, the Black Friars and the Grey Friars. They are known today as the Carmelites, the Augustinians, the Dominicans and the Franciscans, respectively. Friars, unlike monks, live and work among the people and are dedicated to teaching and aiding them, rather than spending their days in religious study or prayer. Friars also depend entirely upon charity, as they shun any kind of wealth.