chef-d'œuvre
/ʃeɪˈdəːvr(ə)
/noun (plural chefs-d'œuvre pronounced same)
A masterpiece: the painting was made after a number of preliminary studies as a self-conscious chef d’oeuvre
Synonyms
masterpiece, masterwork, best work, finest work, greatest creation, crowning achievement, work of art;
treasure, gem, pearl, jewel, jewel in the crown;
Latin magnum opus;
French pièce de résistance, tour de force
Origin
French, 'chief work'.