The Collaborative International Dictionary of English v.0.48:

Walloons \Wal*loons"\, n. pl.; sing. Walloon. [Cf. F. wallon.]
   A Romanic people inhabiting that part of Belgium which
   comprises the provinces of Hainaut, Namur, Li['e]ge, and
   Luxembourg, and about one third of Brabant; also, the
   language spoken by this people. Used also adjectively.
   [Written also Wallons.] "A base Walloon . . . thrust Talbot
   with a spear." --Shak.
   [1913 Webster]

   Walloon guard, the bodyguard of the Spanish monarch; -- so
      called because formerly consisting of Walloons.
      [1913 Webster]

WordNet (r) 3.0 (2006):

Walloons
    n 1: an ethnic group speaking a dialect of French and living in
         southern and eastern Belgium and neighboring parts of
         France