突(忽)然的，出乎意料的(happening，coming，make or done quickly and unexpectedly)：a～attack/idea/departure 突然的攻击/念头/起程;a～burst of temper/turn in the road 突发的一阵脾气/路上的急转弯;the～arrival of the guests 客人们的突然到达;sudden death 暴死;(平局时为决定胜负而延长时间)加赛决胜法;Her decision to get married is rather～. 她要结婚的决定太突然了。〖同〗abrupt，quick，speedy，rapid，immediate，instant，hasty;〖反〗slow，gradual，anticipated;

all of a sudden 突然地，冷不防地，出乎意料地：He was sitting quietly reading when all of a～a stone hurtling through the window. 他正在安静地看书，突然一块石头自窗外飞进室内。

→′suddenly adv 相当突然地;′suddenness n 突然