na-adjective, noun
Describes work, management, or planning that is done without proper care, full of mistakes or oversights. Often used critically.
彼のずさんな管理が問題を引き起こした。
His careless management caused the problem.
ずさんな会計処理が発覚した。
Sloppy accounting practices were uncovered.
noun
unreliable sourcing; error-ridden writing
Specifically refers to a piece of writing that uses unreliable sources or is full of errors. A more literary, less common sense.
その論文は杜撰で、引用が不正確だった。
That paper was sloppy, with inaccurate citations.