Meaning and Name Origin
Marwynn \m(a)-rwy-nn\ as a name for boys. Marwynn's name origin is Welsh, and the name Marwynn means "sea friend". Marwynn is a form of Marvin (Welsh): variant of Mervin. Not often used as a name for children.
Marwynn is a rare first name for males. Marwynn is also a rare surname for all people. (2000 U.S. Census)
Below is a charted comparison of the popularity of the boy name Marwynn and affiliated names. Prominent alternative forms of Marwynn (#unlisted) ranked in the Top 1000 are Marvin (#492 the previous year), Mervyn and Mervin. Adoption of these boy names was at its apex during the years 1930-1939 and has become much less since, with the forms Marvin and Mervin becoming less stylish. (2014 Birth Statistics)