archaic way of saying all of a sudden(古)。 同 all of a sudden
all of a sudden
Very quickly and unexpectedly; suddenly.突然地：非常迅速地和突然地；出乎意料地
英语四级真题
It went bankrupt all of a sudden.
出自-2013年6月阅读原文
It usually appears all of a sudden.
出自-2013年6月听力原文
英语六级真题
right now, to reduce the risk of sudden infant death syndrome, the American Academy of Pediatrics recommends that mothers not sleep in the same bed as their babies, but sleep in the same room.
2016年6月六级真题（第一套）听力 Section B
The sudden decline in foot traffic in recent years, even though it hasn't been accompanied by a massive decline in physical sales, is a critical warning.