migration : Idioms & Phrases
in-migration
-
noun migration into a place (especially migration to a country of which you are not a native in order to settle there)
immigration.
WordNet
migration route
-
noun the geographic route along which birds customarily migrate
flyway.
WordNet
out-migration
-
noun migration from a place (especially migration from your native country in order to settle in another)
emigration; expatriation.