This is the 842nd most frequent Vietnamese word.
bùng
The Vietnamese word "bùng" means to "burst, explode, or break out" or to "skip/ditch" (e.g., skipping an event or responsibility), depending on context.
In this context, 'bùng' is used to describe a sudden and rapid appearance or increase, here referring to the fire.
Lửa bùng lên dữ dội trong căn nhà.
The fire flared up intensely in the house.
Here, 'bùng' conveys the sense of something spreading or erupting quickly, in this case referring to the disease.
Dịch bệnh bắt đầu bùng phát ở khu vực này.
The epidemic started to break out in this area.
In this sentence, 'bùng' is used metaphorically to describe the sudden overexpression of emotions, specifically joy.