1A creative work or piece (of art, literature, film, etc.); used alone or as a suffix to indicate something produced by a particular author or era.
彼の新作が来月公開される。
His new work will be released next month.
その画家の代表作は市立美術館に所蔵されている。
The painter's representative work is held at the city art museum.
近年の作にはテーマ性の強いものが多い。
Many recent works have strong thematic elements.
2A harvest or crop; the yield or result of cultivation (e.g. "this year's crop").
今年の作は天候不順で不作に終わった。
This year's crop ended in a poor harvest due to unfavorable weather.
台風の被害で米の作が大幅に減った。
Because of typhoon damage, the rice yield dropped significantly.
良い肥料を使ったおかげで、葡萄の作が良くなった。
Thanks to using good fertilizer, the grape crop improved.
3Refers to the quality or skill of workmanship in something made — used in phrases like "精巧な作" (finely crafted work) to describe technical quality.
この茶碗は名工の巧みな作だ。
This tea bowl is the skillful work of a master craftsman.
精巧な作の家具は高値で取引される。
Finely crafted furniture sells for a high price.