Source : Webster's Revised Unabridged Dictionary (1913)

Legionary \Le"gion*a*ry\ (-[asl]*r[y^]), a. [L. legionarius: cf.
   F. l['e]gionnaire.]
   Belonging to a legion; consisting of a legion or legions, or
   of an indefinitely great number; as, legionary soldiers; a
   legionary force. ``The legionary body of error.'' --Sir T.
   Browne.

Legionary \Le"gion*a*ry\ (l[=e]"j[u^]n*[asl]*r[y^]), n.; pl.
   {Legionaries} (-r[i^]z).
   A member of a legion. --Milton.

Source : WordNet®

legionary
     n : a soldier who is a member of a legion (especially the French
         Foreign Legion) [syn: {legionnaire}]