A man who retires from the ordinary temporal concerns of the world, and devotes himself to religion; one of a religious community of men inhabiting a monastery, and bound by vows to a life of chastity, obedience, and poverty.
One of the original terms used to describe a consecrated religious*. The root meaning of monk is "mono" meaning one-alone. This oneness described the monk's singleness of purpose (to serve God alone) as well as his vow of chastity by which he had no family. For St. Augustine monk also signified one in the sense of unity with his brothers in community.
Generally, a man who joined a religious house, called a monastery, where he took vows of poverty, chastity and obedience; the commonest form of monk was a man living under the provisions of the Rule of St Benedict. (Lynch, Joseph H. The Medieval Church: A Brief History, 363) Related terms: Nun