/kræk ||; kræk/verb1 [I,T] to break or to make sth break so that a line appears on the surface, but without breaking into pieces （使）出现裂口或裂缝: Don't put boiling water into that glass -- it'll crack. 不要把滚热的水倒进去，那玻璃杯会裂的。The stone cracked the windscreen but didn't break it. 那石块打裂了挡风玻璃，但没有把它砸碎。 ☞picture at chip 见chip插图
2 [T] to break sth open 打破；砸开: Crack two eggs into a bowl. 将两个鸡蛋打进碗里。
3 [I,T] to make a sudden loud, sharp sound; to cause sth to make this sound （使）发出劈啪声: to crack a whip/your knuckles 啪啪地甩鞭子；拧指关节
4 [T] to hit a part of your body against sth; to hit sb with sth （身体部份）撞到，碰到（某物）: She stood up and cracked her head on the cupboard door. 她站起来，头撞着橱柜的门。She cracked the thief over the head with her umbrella. 她用雨伞敲窃贼的脑袋。
5 [I] to no longer be able to deal with pressure and so lose control （由于不能应付压力而）精神崩溃，失控: He cracked under the strain of all his problems. 他在问题重重的压力下精神崩溃了。
6 [I] (used about sb's voice) to suddenly change in a way that is not controlled （指某人的声音）变粗，发哑: Her voice cracked as she spoke about her parent's death. 她说到父母去世时，声音沙哑了。
7 [T] (informal 非正式) to solve a problem 解决（某个问题）: to crack a code 破译密码The police have cracked an international drug-smuggling ring. 警方破获了一个国际毒品走私集团。
8 [T] to tell or make a joke 说笑话；开玩笑: Stop cracking jokes and do some work! 别再开玩笑了，干点活吧！
get cracking (
Brit 英) (
informal 非正式) to start doing sth immediately 立即行动:
I have to finish this job today so I'd better get cracking. 我今天得完成这工作，所以最好还是马上开始。 crack down (on sb/sth) (used about people in authority) to start dealing strictly with bad or illegal behaviour （指掌握权力者）严办，严惩，严厉对待（不良或违法的人或行为）:
The police have started to crack down on drug dealers. 警方已经开始严厉打击毒贩。 crack up 1 (informal 非正式) to be unable to deal with pressure and so lose control and become mentally ill （由于不能应付压力而）失控，精神崩溃: He cracked up when his wife left him. 他的妻子一离开他，他便精神崩溃。
2 (slang 俚语) to suddenly start laughing, especially when you should be serious 突然大笑（尤指在应该严肃的时候）
*crack²/kræk ||; kræk/noun1 [C] a line on the surface of sth where it has broken, but not into separate pieces 裂缝；裂口: a pane of glass with a crack in it 有一处裂缝的窗玻璃 (figurative 比喻) They had always seemed happy together, but then cracks began to appear in their relationship. 他们似乎一直相亲相爱，然后他们的关系开始出现裂缝。 ☞picture at chip 见chip插图
2 [C] a narrow opening 窄缝；狭长的开口: a crack in the curtains 窗帘间的缝隙
3 [C] a sudden loud, sharp sound 劈啪声；爆裂声: There was a loud crack as the gun went off. 开炮了，发出砰的一声巨响。
4 [C] a hard hit on a part of the body 猛烈的一击: Suddenly a golf ball gave him a nasty crack on the head. 突然之间，一个高尔夫球猛然打在他头上，难受极了。
5 [C] (informal 非正式) an amusing, often critical, comment; a joke 俏皮话；笑话: She made a crack about his bald head and he got angry. 她拿他的秃头开玩笑，使他生气。
6 [U] a dangerous and illegal drug that some people take for pleasure and cannot then stop taking 强效纯可卡因；强效纯古柯碱
the crack of dawn very early in the morning 破晓；黎明
have a crack (at sth/at doing sth)(
informal 非正式) to try to do sth 尝试:
I'm not sure how to play but I'll have a crack at it. 我不知道怎样玩，但我想试一试。 crack³/kræk ||; kræk/adj (used about soldiers or sports players) very well trained and skilful （指士兵或运动员）训练有素的，技术精湛的:
crack troops 精锐部队He's a crack shot (= very accurate at shooting) with a rifle. 他打步枪是个神射手。