v. t. to sell or otherwise give up ownership; -- used mostly of artworks in museums.
Syn. -- sell off. [ WordNet 1.5 ]

v. t. [ de- + accession. Ca. 1970. ] to sell (artwork); -- used of sales of art by museums. 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. [ WordNet 1.5 +PJC ]