n(1)机缘，偶然，运气(force that controls the happening of events or way;things happen without any cause or reason that can be seen or understood)[U]：You must leave nothing to～.你决不应靠运气。Let's leave our next meeting to～.咱们下次见面就凭缘分吧。trust to～只凭运气;C～plays an important part.机缘很关键。Let～decide.听天由命吧。It was pure～their meeting in London/that they met in London.他们在伦敦遇上纯粹是偶然。It was a～meeting/encounter/occurrence/happening.这是偶然遇见/遭遇/事件/事件。〖同〗accident，fortune，luck;

(2)可能性(possibility;likelihood;that sth will happen)[C，U][N(of)，N+to-inf，N+that]：There's no～of success/a rise/getting a ticket/that.成功/涨工资/弄到票/那没有可能。What is(are)our～(s)of success/succeeding?(What is(are)the～(s) of our success/succeeding?What～of success/succeeding do we have?)我们成功的可能性如何?He has no～/not much～/only a slim～/a good～of winning.他没有/不大/很不/很有可能赢。stand very little/a good～of winning几乎没有/很有可能赢;There is little (a)～that he'll get well/the situation will improve.他几乎没有(有)可能康复/形势几乎没有(有)可能好转。(The) C～s are that you will win/the train hasn't left yet.很有可能你会赢/火车还没有开。〖同〗possibility，likelihood，likeliness;probability;〖反〗impossibility，unlikelihood， improbability;

(3)(好)机会(favourable situation;opportunity)[C][N(of)，N+to-inf]：This is your big～!你的好机会来了!It was his one big～to succeed.这是他成功的大好机会。have (get) a good～of success/escape/going there有一个成功/逃跑/去那儿的好机会;get (have/give sb) a～to explain有(有/给某人)机会解释;get(have/give sb)no～to talk to sb else没有(没有/不给某人)机会与别人交谈;ignore/miss a～to do sth忽视/错过做某事的机会;〖同〗opportunity;

(4)冒险(risk or gamble)[C][N(of)]：take many～s in one's attempt to win the race企图赢得赛跑要冒很大风险;Don't take～s by driving too fast.不要冒险超速行车。That's a～we'll have to take.我们只好冒一下险了。You might take a～.你可以冒一把险。There's an element of～in this business deal.这桩生意有点风险。〖同〗risk;

by chance 偶然，碰巧：I found it/met him only by～.我只是碰巧找到这个/遇到他的。It was by sheer～that I found out the truth.我发现事实真相纯属偶然。

by any chance也许，可能：Are you by any～free to come to the theatre tonight? 你今晚上有空去看戏吗?

v(1)碰巧，偶然，刚好(happen accidentally or unexpectedly)[I+to-inf，I]：I～d to be passing/to overhear them.我刚好路过/碰巧听见了他们的谈话。It (so)～d that I was passing by/he was there. 我碰巧路过/他碰巧在那里。〖同〗happen，occur;

(2)冒险，碰运气(risk;take a chance with)[T+n，T+-ing]：～another game of cards/another throw of the dice再玩一次牌/赌一次试试;～the possibility of being caught/all one's money (on a horse) at once冒可能被抓住的危险/把所有的钱孤注一掷(押在一匹马上);I'll have to～it，whatever the outcome may be.我只好不管结局如何冒一下险了。～meeting an enemy patrol冒遇上敌人巡逻队的危险;〖反〗risk，attempt;

【辨异】1)chance与luck和fortune都有“运气”的意思。chance是无法预见和理解的偶然机缘，如：By some strange chance we discovered the error.(由于某种莫名其妙的运气，我们发现了那个错误。)luck所指的运气较具体，可能是好运，也可能是坏运，如：I have had bad/good luck all week.(我一个礼拜尽走坏运/好运。)fortune指对人的一生起重要作用的“命运”，或未来的“运气”，如：What will be our fortune? (我们的命运(运气)将会如何?) 2)chance与opportunity和occasion皆可指适合做某事的“时机”。chance与opportunity都可表示“机会”，用法也相近，可互换，指做某事所需的客观条件已具备的时刻，如：I had the chance/opportunity to visit/of visiting Paris.(我有机会参观巴黎。)但注意，下句中的chance不可用opportunity代替：There is a chance that you'll see him.因为句中的chance当“可能性”讲(见(2))，opportunity无这种语义，也无这种用法。occasion(时机，机会)指有可能做某事的特定时刻，如：If the occasion arrives，I'll speak to him.(如果有机会我要和他谈话。)此字也无“可能性”的意思。3)chance与happen和occur都可表示“发生”。chance指“意外”、“偶然”发生，语体色彩较为正式，如：It chanced to rain that day.(那天碰巧下雨。)happen可指一般的发生，也可指“意外”、“偶然”发生，是最通常用词，如：It happened yesterday.(这事发生在昨天。)I happened to be there.(我碰巧在那里。)occur的语体色彩较happen正式，时间和事情本身更具体，如：His death occurred the following year.(第二年他死了。) 还有短语take place，指计划中的事情发生，如：The funeral took place the following day.(第二天举行了葬礼。)