プログレッシブ和英中辞典(第4版)の解説
ておち【手落ち】
〔過失〕a fault；〔手抜かり〕an omission
荷物が着かなかったのは彼の手落ちだった
It was his fault that our luggage did not arrive.
それはみんなの手落ちだった
We were all at fault.
結婚式の用意はすべて手落ちなく行われた
All the preparations for the wedding were made 「most carefully [with the utmost care].