The Collaborative International Dictionary of English v.0.48:

Wen \Wen\ (w[e^]n), n. [AS. wenn; akin to D. wen, LG. wenne.]
   (Med.)
   An indolent, encysted tumor of the skin; especially, a
   sebaceous cyst.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Wyn \Wyn\, Wynn \Wynn\, n. Also Wen \Wen\ [AS. w[=e]n.]
   One of the runes (?) adopted into the Anglo-Saxon, or Old
   English, alphabet. It had the value of modern English w, and
   was replaced from about a. d. 1280 at first by uu, later by
   w.

WordNet (r) 3.0 (2006):

wen
    n 1: a common cyst of the skin; filled with fatty matter (sebum)
         that is secreted by a sebaceous gland that has been blocked
         [syn: sebaceous cyst, pilar cyst, wen,
         steatocystoma]