It's the immodest title of the 1912 Marcel Duchamp painting seen here
Before its first presentation at the Parisian 1912 Salon des 
Indpendants, ... At the bottom left Duchamp placed the title "NU DESCENDANT 
UN... [DOC] [TLE] Marcel Duchamp - Wikipedia [PAR] Henri-Robert-Marcel Duchamp was a French, naturalized American painter, 
sculptor, chess ....