| Noun | 1. | migration - the movement of persons from one country or locality to anotherimmigration, in-migration - migration into a place (especially migration to a country of which you are not a native in order to settle there) movement, move, motion - the act of changing location from one place to another; "police controlled the motion of the crowd"; "the movement of people from the farms to the cities"; "his move put him directly in my path" gold rush - a large migration of people to a newly discovered gold field | |
| 2. | migration - a group of people migrating together (especially in some given time period)people - (plural) any group of human beings (men or women or children) collectively; "old people"; "there were at least 200 people in the audience" | |
| 3. | migration - (chemistry) the nonrandom movement of an atom or radical from one place to another within a moleculeevent - something that happens at a given place and time chemical science, chemistry - the science of matter; the branch of the natural sciences dealing with the composition of substances and their properties and reactions | |
| 4. | migration - the periodic passage of groups of animals (especially birds or fishes) from one region to another for feeding or breeding | |