noun, na-adjective
great success; happy result
Describes a favorable outcome, often used in formal or business contexts. Can function as a noun or na-adjective.
Antonyms: 不首尾
交渉は上首尾に終わった。
The negotiations ended successfully.
プロジェクトが上首尾だったので、皆で祝った。
The project was a great success, so we all celebrated.