Merwyn \m(e)-rw-yn\ as a boy's name is a variant of Marvin (Welsh), Merton (Old English) and Mervin (Old Welsh), and the meaning of Merwyn is "sea friend; town by the lake".

The baby name Merwyn sounds like Merwin, Marwynn, Marwin and Merwinn. Other similar baby names are Berwyn, Derwyn, Kerwyn, Mervyn, Medwyn, Melwyn and Merlyn.