The Collaborative International Dictionary of English v.0.48:

Marseillais \Mar`sei`llais"\, n. m. Marseillaise
\Mar`sei`llaise"\, n. f.[F.]
   A native or inhabitant of Marseilles.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Marseillais \Mar`sei`llais"\, a. m. Marseillaise
\Mar`sei`llaise"\, a. f.[F.]
   Of or pertaining to Marseilles, in France, or to its
   inhabitants.
   [1913 Webster]

   Marseillaise hymn, or The Marseillaise, the national
      anthem of France, popularly so called. It was composed in
      1792, by Rouget de l'Isle, an officer then stationed at
      Strasburg. In Paris it was sung for the first time by the
      band of men who came from Marseilles to aid in the
      revolution of August 10, 1792; whence the name.
      [1913 Webster] Marseillais

WordNet (r) 3.0 (2006):

Marseillaise
    n 1: the French national anthem