failed work; flop; dud
Refers to a creative work (film, book, art, etc.) that turned out poorly or was unsuccessful. Often used in critical or self-deprecating contexts.
His new movie is said to be a flop.
This painting is a failure, so I'll redo it.
失敗作 is a work that flopped or failed, contrasting with ヒット作 which succeeded commercially.
Compound of 失敗 (failure) + 作 (work, production).