migration

American  

[mahy-grey-shuhn] / maɪˈgreɪ ʃən /

noun

1. the process or act of migrating.

2. a migratory movement.

   preparations for the migration.

3. a number or body of persons or animals migrating together.

4. Chemistry. a movement or change of position of atoms within a molecule.

5. Physics. diffusion.

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migration British  

/ maɪˈɡreɪʃən /

noun

1. the act or an instance of migrating

2. a group of people, birds, etc, migrating in a body

3. chem a movement of atoms, ions, or molecules, such as the motion of ions in solution under the influence of electric fields

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migration Scientific  

/ mī-grā′shən /

1. The seasonal movement of a complete population of animals from one area to another. Migration is usually a response to changes in temperature, food supply, or the amount of daylight, and is often undertaken for the purpose of breeding. Mammals, insects, fish, and birds all migrate. The precise mechanism of navigation during migration is not fully understood, although for birds it is believed that sharp eyesight, sensibility to the Earth's magnetic field, and the positions of the Sun and other stars may play a role.

2. The movement of one atom or more, or of a double bond, from one position to another within a molecule.

3. The movement of ions between electrodes during electrolysis.

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Other Word Forms

• migrational adjective
• nonmigration noun
• premigration adjective
• remigration noun

Etymology

Origin of migration

First recorded in 1605–15, migration is from the Latin word migrātīon- (stem of migrātiō ). See migrate, -ion

Explanation

Migration is the movement of either people or animals from one area to another. Look up in the trees, where you might see a Monarch butterfly make a stop on its migration to Mexico. Migration can be used for the journey from one place to another or for the act of movement. Thousands of mid-western farmers made the migration to California during the dust bowl. Demographers have noted the migration of young people to the big cities presumably for work. With animals, it’s almost always in reference to a seasonal change in location. On boat tours, you can see the whales during their annual migration down the West coast.

Example Sentences

Plaid Cymru said it "wants a fair, rules-based system of controlled migration that works for Wales, meets the needs of our communities, reflects Wales' unique challenges, and that upholds our values".

From BBC • Apr. 23, 2026

International migration figures include people planning to stay for at least 12 months, such as British nationals returning to Wales from abroad as well as those moving from other countries.

From BBC • Apr. 23, 2026

The first batch of deportees arrived last Friday in the central African country under a controversial US migration scheme to pack off undocumented foreign nationals to third countries.

From Barron's • Apr. 22, 2026

The acting director of the agency central to the Trump administration’s migration crackdown is set to leave the department in May.

From The Wall Street Journal • Apr. 21, 2026

“Although I’ve just returned from my most recent migration, I’ve visited the area many times and never took issue.”

From "The Very, Very Far North" by Dan Bar-el

Related Words

• exodus
• flight
• journey
• movement
• shift
• transfer