chef d'œuvre

Etymology
Borrowed from.

Noun

 * 1) A piece of work that has been given much critical praise, especially one considered the greatest work of a person's career.
 * 2) * 1872, James Legge translating Confucius as The Ch‘un Ts‘ew, Prolegomena, Ch. iv, Sect. i, p. 139
 * Ch‘ing Twan-hëoh... took his third degree in 1,321. He was much employed in the office of historiography, and composed the Work next mentioned and another on the Ch‘un Ts‘ëw before he felt equal to this, which is reckoned his chef d'œuvre.
 * 1) A work of outstanding creativity, skill or workmanship.
 * 2) A work created in order to qualify as a master craftsman and member of a guild.