noun
Used for agricultural produce (a good harvest) or for a well-made work (a fine piece of art, writing, etc.). The two glosses represent distinct domains; context makes the intended meaning clear.
今年は天候に恵まれて上作だった。
Thanks to good weather, we had a good crop this year.
この小説は彼の上作の一つだ。
This novel is one of his masterpieces.