The boy's name Allen a(l)-len is pronounced AL-en. It is of Gaelic origin. Variant of Alan (OldGerman) "precious". Allen is an English and American preference; Allan is Scottish. See also Alain.Allen has 2 variant forms: Allan and Allyn.Baby names that sound like Allen are Allon, Allin, Alleyn and Alen. Allen is a very popular male first name and a very popular surname (source: 1990 U.S. Census). Displayed below is the baby name popularity trend for the boy's name Allen. Compare Allen with related baby names. Got info from this link: www.babynames.com