Originally Posted by
cb400bill
de·ac·ces·sion (dk-sshn)
v. de·ac·ces·sioned, de·ac·ces·sion·ing, de·ac·ces·sions
v.tr.
To remove and sell (a work of art) from a museum's collection, especially in order to purchase other works of art: "He also denied that ... friends of the museum were permitted to buy ... pieces that were deaccessioned" New York Times.
It also refers to a library removing books or other materials from its collection. The staff members responsible for acquiring new materials for a library usually are known as the Accessions Department.
(Yes, I'm a former librarian. I was in charge of the Cataloging Department, but we all worked together on accessions/deaccessions.)