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

Etymology

Origin of accession

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

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 added that "Albanian legislation will have to be aligned with the EU" before the crucial Chapter 27 environmental elements of the accession talks, relating to waste management, water and air quality, "can be closed".

From Barron's ● Oct. 8, 2026

Fishing is big business in Iceland, and European countries were unwilling to promise they wouldn’t use accession talks as leverage for access to Icelandic waters.

From The Wall Street Journal ● Sep. 7, 2026

However, in the wake of the 2008 financial crisis and the collapse of Iceland's banking system, Reykjavik moved to start accession talks in 2009, only to bring them to a halt in 2013.

From BBC ● Aug. 29, 2026

It would mean backing a move towards an accession agreement.

From BBC ● Aug. 29, 2026

Now my body seemed at last to say, “Well, if you must have it, here!” and an accession of strength came flooding through me.

From "A Separate Peace" by John Knowles

Related Words

• enlargement
• extension