migration into a place (especially migration to a country of which you are not a native in order to settle there) | the movement of persons from one country or locality to another |
the body of immigrants arriving during a specified interval | the periodic passage of groups of animals (especially birds or fishes) from one region to another for feeding or breeding |
| (chemistry) the nonrandom movement of an atom or radical from one place to another within a molecule |
| a group of people migrating together (especially in some given time period) |