To blunder or fail to do something; to miss an important opportunity or make a mistake in a task or procedure.
試験で計算を仕損じてしまい、合格点に届かなかった。
I botched the calculations on the exam and didn't reach the passing mark.
重要書類の提出を忘れて、契約の機会を仕損じた。
I forgot to submit an important document and missed the chance to sign the contract.
彼はプレゼンで説明を仕損じ、相手の信頼を損ねた。
He messed up the explanation in the presentation and lost the client's trust.