Source : Webster's Revised Unabridged Dictionary (1913)

Manx \Manx\, a.
   Of or pertaining to the Isle of Man, or its inhabitants; as,
   the Manx language.

   {Manx cat} (Zo["o]l.), a breed of domestic cats having a
      rudimentary tail, containing only about three vertebrae.
      

   {Manx shearwater} (Zo["o]l.), an oceanic bird ({Puffinus
      anglorum}, or {P. puffinus}), called also {Manx petrel},
      {Manx puffin}. It was formerly abundant in the Isle of
      Man.

Manx \Manx\, n.
   The language of the inhabitants of the Isle of Man, a dialect
   of the Celtic.

Source : WordNet®

Manx
     adj : of or relating to the Isle of Man or its inhabitants or
           their language; "the Manx fishing industry"; "there are
           few Manx speakers alive today"

Manx
     n : the Gaelic language formerly spoken on the Isle of Man