accession

American  

[ak-sesh-uhn] / ækˈsɛʃ ən /

noun

1. the act of coming into the possession of a right, title, office, etc..

   accession to the throne.

2. an increase by something added.

   an accession of territory.

3. something added.

   a list of accessions to the college library.

4. Law. addition to property by growth or improvement.

5. consent; agreement; approval.

   accession to a demand.

6. International Law. formal acceptance of a treaty, international convention, or other agreement between states.

7. the act of coming near; approach.

8. an attack or onset, as of a disease.

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verb (used with object)

1. to make a record of (a book, painting, etc.) in the order of acquisition.

2. to acquire (a book, painting, etc.), especially for a permanent collection.

accession British  

/ əkˈsɛʃən /

noun

1. the act of entering upon or attaining to an office, right, condition, etc

2. an increase due to an addition

3. an addition, as to a collection

4. property law

   1. an addition to land or property by natural increase or improvement

   2. the owner's right to the increased value of such land

5. international law the formal acceptance of a convention or treaty

6. agreement; consent

7. a less common word for access

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verb

1. (tr) to make a record of (additions to a collection)

Other Word Forms

• nonaccession
  noun
• reaccession
  noun
• accessional
  adjective
• unaccessional
  adjective

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Etymology

Origin of accession

1580–90; < Latin accessiōn- (stem of accessiō ) an approach, addition. See access, -ion

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Explanation

Accession is the act of advancing into a position. Being elected class president is a kind of accession. Accession originally referred to a queen or king taking the throne. From the Latin term, accessionem, meaning "joining or increasing,” accession may refer to the gaining of access to any formal position, group, or right. It can also mean “agreement” — think of it as “joining in.” Accession may also refer to property — either something that increases your original collection, or the right to all of your property even through growth — such as the golden egg your new hen laid.

Example Sentences

See Examples For:

accession

It was granted official candidate status a few months later, with accession negotiations kicking off in 2024.

From Barron's ● Oct. 7, 2026

Meanwhile, countries like Sweden and Finland for years remained nonaligned but maintained strong armed forces, said Tobias Billström, who was the Swedish foreign minister during the country’s accession to NATO.

From The Wall Street Journal ● Sep. 15, 2026

Since the accession of King Charles III in 2022, those suggestions have included On His Majesty's Secret Service, and King & Country.

From BBC ● Sep. 6, 2026

It would mean backing a move towards an accession agreement.

From BBC ● Aug. 29, 2026

The accession of fortune, the discovery of my relations, followed in due order.

From "Jane Eyre" by Charlotte Brontë

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