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.
彼の新作映画は失敗作だと言われている。
His new movie is said to be a flop.
この絵は失敗作だから、もう一度描き直す。
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).