The Collaborative International Dictionary of English v.0.48:

Neif \Neif\, Neife \Neife\ (n[=e]f), n. [OF. ne["i]f, na["i]f, a
   born serf, fr. L. nativus born, imparted by birth. See
   Native.]
   A woman born in the state of villeinage; a female serf.
   --Blackstone.
   [1913 Webster] Neif