プログレッシブ和英中辞典(第4版)の解説
くろぼし【黒星】
&fRoman1;〔黒い点〕a black spot [dot]；〔的の中心〕the bull's-eye
&fRoman2;〔負け〕a loss；〔失敗〕a failure
黒星を取る
lose a point／be beaten／be defeated
このところ黒星続きだ
I am in the middle of a losing streak.／〔失敗続き〕I have made one mistake after another.
あの答弁は彼の黒星だった
His own reply gave him a black eye [mark].
あの事件は警察の黒星だった
The police mishandled [made a blunder in] that case.