accession

Sense 1 noun

a process of increasing by addition (as to a collection or group)

the art collection grew through accession

Sense 2 verb

make a record of additions to a collection, such as a library

Sense 3 noun

(civil law) the right to all of that which your property produces whether by growth or improvement

Sense 4 noun

something added to what you already have

the librarian shelved the new accessions

Sense 5 noun

agreeing with or consenting to (often unwillingly)

accession to such demands would set a dangerous precedent

Sense 6 noun

the right to enter

Sense 7 noun

the act of attaining or gaining access to a new office or right or position (especially the throne)

Elizabeth's accession in 1558