ˈæksɛs ˈækˌsɛs æk.ˈsɛ.ʃən æk.ˈsɛ.ʃən əˈdɪʃən ædˈmɪʃ.ən ədˈmɪt.n̩s the act of attaining or gaining access to a new office or right or position (especially the throne) Elizabeth's accession in 1558 make a record of additions to a collection, such as a library 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