Source : Webster's Revised Unabridged Dictionary (1913)

Migratory \Mi"gra*to*ry\, a. [Cf. F. migratoire.]
   1. Removing regularly or occasionally from one region or
      climate to another; as, migratory birds.

   2. Hence, roving; wandering; nomad; as, migratory habits; a
      migratory life.

   {Migratory locust} (Zo["o]l.) See {Locust}.

   {Migratory thrush} (Zo["o]l.), the American robin. See
      {Robin}.

Source : WordNet®

migratory
     adj 1: used of animals that move seasonally; "migratory birds"
            [ant: {nonmigratory}]
     2: habitually moving from place to place especially in search
        of seasonal work; "appalled by the social conditions of
        migrant life"; "migratory workers" [syn: {migrant}]