black spot

Từ điển Oxford Advanced Learner 8th

ˈblack spot [black spot black spots] BrE NAmE noun (BrE)
a place, a situation or an event that is a problem or that causes a lot of problems
•an environmental black spot
•That corner is a notorious accident black spot (= a lot of accidents happen there).
•The one black spot on the horizon is that the team's sponsorship will be reduced next year.