Definition from Wiktionary, the free dictionary
masterwork (plural masterworks)
- A piece done to prove possession of skill sufficient to be ranked a master.
- A piece of quality, indicative of having been made by a master; a masterpiece.
- (obsolete) An act of primary importance.
- (obsolete) A main drain or irrigation channel.
piece done to be ranked a master
piece of quality indicative of having been made by a master — see masterpiece