The Collaborative International Dictionary of English v.0.48:

Lipans \Li*pans"\ (l[-e]*p[aum]nz"), n. pl.; sing. Lipan
   (l[-e]*p[aum]n"). (Ethnol.)
   A tribe of North American Indians, inhabiting the northern
   part of Mexico. They belong to the Tinneh stock, and are
   closely related to the Apaches.
   [1913 Webster]