1. A process in which human populations go from one regiion to another one; usually, resulting in cultural contact with their new environments.
2.A group of birds, fish, or other animals that are going together from one region or country to another for feeding or breeding purposes.
3. A group of people moving together; especially, in some given time period.
4. In chemistry, the movement of ions under the influence of an electric field.
5. The movement of an atom, or a group of atoms or double bonds, from one part of a molecule to another.
6. A transfer of computer data, programs, or hardware from one system to another.
7. The movement of oil, gas, contaminants, water, or other liquids through porous and permeable rock.
8. A condition or process of extraction, in which an aqueous or organic solvent selectively dissolves part of an adhesive film and carries it to a different location as the solvent evaporates.

General biological migrations

Animal migration is a predictable, recurring group movement that is characteristic of the members of a given species, and which occurs regularly in response to seasonal changes in temperature, precipitation, food availability, etc.

The process usually involves a round-trip movement between two areas, to seek a more suitable breeding place, a greater food and water supply, or other more favorable environmental conditions.

A pattern in which certain birds travel great distances from their point of origin, or hatching, to continue their adult lives: The return migration is done in response to seasonal climatic conditions so they can go back to where they came from in order to lay eggs and to rear their young.