Medieval variant of Mervyn, resulting from the regular Middle English change of -er- to -ar-. Modern use may represent a transferred use of the surname derived from this in the Middle Ages. It is popular in the United States, where it is associated in particular with the American singer Marvin Gaye (1939–84) and the boxer Marvin Hagler (b. 1954).
Irish: Anglicized form of Gaelic Ó Brádaigh ‘descendant of Brádach’, a byname the meaning of which is not clear. It is unlikely to be connected with Gaelic bradach ‘thieving’, ‘dishonest’, which has a short first vowel.