chef d'oeuvre

noun3

1. •
   A piece of work that has been given much critical praise, especially one considered the greatest work of a person's career.

   • It was there that the Romans exposed their chefs-d’oeuvre of painting and of sculpture. — 1807
2. •
   A work of outstanding creativity, skill or workmanship.
3. •
   A work created in order to qualify as a master craftsman and member of a guild.