/ Dictionary / Index A accession: Meaning and Definition of Find definitions for: ac•ces•sion Pronunciation: (ak-sesh'un), [key] — n. the act of coming into the possession of a right, title, office, etc.: accession to the throne. an increase by something added: an accession of territory. something added: a list of accessions to the college library. addition to property by growth or improvement. consent; agreement; approval: accession to a demand. formal acceptance of a treaty, international convention, or other agreement between states. the act of coming near; approach. an attack or onset, as of a disease. —v.t. to make a record of (a book, painting, etc.) in the order of acquisition. to acquire (a book, painting, etc.), esp. for a permanent collection. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: accession (Thesaurus) accessible accession number Related Content Daily Word Quiz: profiterole Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language