Michael Callahan

(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.

Irish: reduced Anglicized form of Gaelic Ó Ceallacháin ‘descendant of Ceallachán’, a diminutive of the personal name Ceallach, possibly meaning ‘lover of churches’, from ceall ‘church’, or (more likely) ‘bright-headed’, from cen ‘head’ + lach ‘light’. This name was borne by a 10th-century king of Munster, from whom many present-day bearers of the surname claim descent.