やりそこない

noun

failure; blunder; slip-up

Refers to a mistake or botched attempt, often implying a careless or clumsy error. Derived from the verb やり損なう (to fail in doing).

See also: 遣り損なう (やりそこなう)

• 彼かれのやり損そこないでプロジェクトが遅おくれた。

  The project was delayed because of his blunder.

• ちょっとしたやり損そこないが大おおきな問もん題だいになった。

  A small slip-up turned into a big problem.