A long work (e.g., a novel or film) of considerable length; used for long-form novels or movies.
彼は長編小説の執筆に三年かけた。
He took three years to write his long novel.
その監督は長編映画で国際的に評価された。
That director was internationally acclaimed for a feature-length film.
短編では表現しきれないテーマを長編で描いた。
He portrayed themes that couldn't be fully expressed in a short work by using a long-form piece.