The Collaborative International Dictionary of English v.0.48:

Lynx \Lynx\ (l[i^][ng]ks), n. [L. lynx, lyncis, Gr. ly`gx; akin
   to AS. lox, G. luchs, prob. named from its sharp sight, and
   akin to E. light. See Light, n., and cf. Ounce an
   animal.]
   1. (Zool.) Any one of several species of feline animals of
      the genus Felis, and subgenus Lynx. They have a short
      tail, and usually a pencil of hair on the tip of the ears.
      [1913 Webster]

   Note: Among the well-known species are the European lynx
         (Felis borealis); the Canada lynx or loup-cervier
         (Felis Canadensis syn. Lynx lynx); the bay lynx of
         America (Felis rufa), and its western spotted variety
         (var. maculata); and the pardine lynx (Felis pardina)
         of Southern Europe.

   2. (Astron.) One of the northern constellations.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Bay \Bay\ (b[=a]), a. [F. bai, fr. L. badius brown,
   chestnut-colored; -- used only of horses.]
   Reddish brown; of the color of a chestnut; -- applied to the
   color of horses.
   [1913 Webster]

   Bay cat (Zool.), a wild cat of Africa and the East Indies
      (Felis aurata).

   Bay lynx (Zool.), the common American lynx (Lynx lynx,
      formerly Felis rufa or Lynx rufa).
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Felis \Fe"lis\ (f[=e]"l[i^]s), prop. n. [L., cat.] (Zool.)
   A genus of mostly small carnivorous mammals, including the
   domestic cat, puma, ocelot, and margay, which share the
   inability to roar due to bone structure in the larynx. The
   lion, tiger, and other large roaring cats were once included
   in Felis but are now assigned to the genus Panthera. The
   lynx (Felis lynx) is also called Lynx lynx.
   [1913 Webster +PJC]

WordNet (r) 3.0 (2006):

Lynx lynx
    n 1: of northern Eurasia [syn: common lynx, Lynx lynx]