What is "de-accession"

deaccession \deaccession\, de-accession \de-accession\v. t. [de- + accession. Ca. 1970.] to sell (artwork); -- used of sales of art by museums.

Note: The word appears to have been coined as a euphemism to avoid the negative connotations of the word ``sell'', particularly for works donated by benefactors. The practise is justified as a means of acquiring funds for purchase of more valuable artworks.