Definition
A minor issue or annoyance that spoils something that would otherwise be positive or pleasant.
美中不足之处；令人扫兴的人或事物。
The project was progressing smoothly, with the only fly in the ointment being that the budget had been exceeded slightly.
项目进展顺利，唯一的美中不足是预算稍微超支了。
The hotel was perfect, the only fly in the ointment being the slow internet speed.
酒店很完美，唯一的美中不足是网速很慢。
The wedding was wonderful, but the only fly in the ointment was the bride’s slightly ill-fitting dress.
婚礼非常美好，唯一的美中不足是新娘的礼服稍微有点不合身。