Michael Duff

(male) English form of a common biblical name (meaning ‘who is like God?’ in Hebrew) borne by one of the archangels, the protector of the ancient Hebrews, who is also regarded as a saint of the Catholic Church. In the Middle Ages, Michael was regarded as captain of the heavenly host (see Revelation 12:7–9), symbol of the Church Militant, and patron of soldiers. He was often depicted bearing a flaming sword. The name is also borne by a Persian prince and ally of Belshazzar mentioned in the Book of Daniel. Since the early 1900s it has been one of the most enduringly popular boys' names in the English-speaking world. See also Michal.

Scottish and Irish: reduced Anglicized form of Gaelic Ó Duibh (‘descendant of Dubh’), Mac Giolla Duibh (‘son of the servant of Dubh’), or a short form of Duffin 2 (County Wexford), MacElduff (County Tyrone; see Kilduff), Mac Duibh, and Duffy, all of which are formed from personal names containing the element dubh ‘dark’, ‘black’ (widely used as a nickname or byname for a dark-haired man or man of dark temperament and as an element of personal names).