accession

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

Elizabeth's accession in 1558

the right to enter

agreeing with or consenting to (often unwillingly)

accession to such demands would set a dangerous precedent

assenting to the Congressional determination

something added to what you already have

the librarian shelved the new accessions

he was a new addition to the staff

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

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

the art collection grew through accession

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