An object of art becoming part of a permanent collection of a museum or other collection. It is the opposite of de-accession. Source: with permission of Michael Delahunt.<br><br>A museum&#39;s act of acquiring an object so that the artwork becomes a part of its permanent collection, or, by extension, the acquiring of a piece by any collector. Or an object so acquired. Or the act of recording and processing an addition to a permanent collection. The opposite of accession is deaccession.Also see collection, commodification, donation, and register.