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).
Scottish: habitational name from any of four places so called. One in Fife is found in old records (1128) as Pettnaurcha, a Pictish-Gaelic name meaning ‘the portion of the shot’. Others, including one on Loch Ness, are named with Welsh ar ‘on’, ‘by’ + cardden ‘thicket’.