migration (Noun) — The movement of persons from one country or locality to another.
migration (Noun) — A group of people migrating together (especially in some given time period).
migration (Noun) — (chemistry) the nonrandom movement of an atom or radical from one place to another within a molecule.
migration (Noun) — The periodic passage of groups of animals (especially birds or fishes) from one region to another for feeding or breeding.
migration (Noun) — (computing) the process of changing from one computing system to another.