The Collaborative International Dictionary of English v.0.48:

Manx \Manx\, prop. n.
   The language of the inhabitants of the Isle of Man, a dialect
   of the Celtic.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Manx \Manx\, a.
   Of or pertaining to the Isle of Man, or its inhabitants; as,
   the Manx language.
   [1913 Webster]

   Manx shearwater .
      [1913 Webster]

WordNet (r) 3.0 (2006):

Manx
    adj 1: 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"
    n 1: the ancient Gaelic formerly spoken on the Isle of Man; the
         language is sometimes used on ceremonial occasions
    2: a short-haired tailless breed of cat believed to originate on
       the Isle of Man [syn: Manx, Manx cat]