Meaning and Name Origin
Kirwen \k(i)-rwen, kir-wen\ as a boys' name. The name Kirwen means "little dark one". Kirwen is a derivative of Kerwin (Irish): also possibly (Old English) "swamp friend". A seldom-used given name for boys.
Kirwen is an uncommonly occurring first name for men. Kirwen is an equivalently unusual last name too for all people. (2000 U.S. Census)
Below is a graphed comparison of the popularity of the boy name Kirwen and associated names. Kerwin is the only popular alternative form of Kirwen (#unlisted) ranked in the Top 1000. Adoption of this boy name was at its highest during the years 1960-1969 and is now less. (2014 Birth Statistics)