sud‧den S2 W3 / sʌdn / 形容词

1 happening, coming, or done quickly or when you do not expect it :

a sudden change in the weather

Life is cruel, she thought, with a sudden rush of anger.

a sudden movement

Her death was sudden.

2 all of a sudden suddenly :

All of a sudden the lights went out.

— suddenness 名词 [不可数名词]