(1)(意外)事故(灾祸)(unexpected happening，often causing damage，injury，loss，death，etc)[C，U(without～)]：have (meet with) a road/traffic～出交通/交通事故;have (meet with) a car/motoring/carriage/bicycle/railway～出汽车/汽车/马车/自行车/火车车祸;have an～at work/at home 工作时/在家里出了事故; be killed/break one's leg in a skiing～在一次滑雪事故中丧生/跌断了腿;A sad/bad/slight～happened (occurred).发生了一起可悲/糟糕/小小的事故。A～s will happen.(prov)不幸的事在所难免。without～平安无恙地;～insurance 意外伤害保险;the scene of an～事故地点;〖同〗crash，wreck，mischance;

(2)偶然发生的事(any event that happened unexpectedly)[C]：It was just/quite an～that I found the missing letter.我发现那封丢失的信纯属偶然。Our meeting was a mere～.我们的见面纯粹是偶然。The discovery was a happy～.这一发现令人意外地高兴。The fact is due to a historic～.这一事实是由于历史的偶然造成的。〖同〗chance;〖反〗plan，intention，design;

(3)机遇;幸运(chance;fortune;luck)[U]：Columbus discovered America by～.哥伦布意外地发现了美洲。run across sb/meet sb/be somewhere quite by～极其偶然地碰上某人/遇见某人/在某处;It was quite by～that we arrived together.我们一块到达完全是巧合。By～of birth he was rich.他富有是因为投胎到了有钱人家。〖同〗chance，luck，fortune;

→ ͵acci′dental adj 意外(偶然)的;͵ac-ci′dentally adv 意外(偶然)地;′accident-prone adj 特别易出事故的