1.sweat作名词时意思是“汗”,转化成动词意思是“出汗”,指由于工作辛苦或某种心情而使汗液渗出。引申可指“辛苦工作”。
2.sweat可用作及物动词,也可用作不及物动词。用作及物动词时,后接名词或代词作宾语。
3.sweat的过去式和过去分词有两种形式,分别是sweat和sweated。

sweat for(v.+prep.)
〈非正〉付出巨大的努力而得到… gain (sth) by great effort
〔说明〕 sweat for常不用于进行体。
▲sweat for sth
The other team won the prize, but we made them sweat for it!那个队得奖了,可我们也让他们赢得不轻松。

sweat off(v.+adv.)
由于出汗而减轻 close (weight) by losing liquid from the body
▲sweat off
In the steam bath, he sweated off two pounds in an hour.他洗蒸汽浴时出了一身大汗,体重在一小时内就减轻了两磅。

sweat out(v.+adv.)
1.以发汗来驱逐 remove or get rid of (sth) by getting hot and losing liquid from the body
▲sweat sth⇔out
She sweated out her cold.她发了一身汗治好了伤风。
When you feel flu coming on, get into bed and sweat it out.当你开始觉得有点感冒时,赶快上床去,出身汗就好了。
2.拼命工作 work very hard indeed
▲sweat one's guts out
Why should I sweat my guts out for only twelve pounds a week?一周只给12镑,我为何要拼命干呢?
Here I've been sweating my guts out all afternoon, and hardly anything to show for it!我在这儿玩命干了一下午,可几乎不见成效。
3.忍耐到最后 wait for the end or arrival of sth in discomfort; suffer sth unpleasant till it ends
▲sweat it out
Don't throw up your job, sweat it out a bit longer.不要轻易放弃你的工作,再忍受一阵子。
It was a terrible performance, but I felt I had to sweat it out.节目太差了,可我还得耐着性子看下去。

用作不及物动词
▲S+～(+A)
He sweated during the night.他晚上盗汗。
The long hot climb made him sweat.长距离的激烈攀登使他出汗了。
He was sweating after working so hard.他拼命干活后正在出汗。
He was sweating like a bullock.他正在牛马似地干活。
用作及物动词
▲S+～+n./pron.
The doctor sweated his patient.医生使他的病人发汗。
He sweated his horse by riding it too hard.他拼命骑马,使马累出一身汗。
You should try to sweat the surplus moisture.你应该设法使多余的水分渗出。
The boss sweated his workers.老板让他的工人们辛辛苦苦地工作。

［派生词］ sweaty adj.浑身出汗的,汗臭的;闷热的;热得使人出汗的‖sweatily adv. 浑身出汗地；热得使人出汗地‖ sweatiness n. 浑身出汗；闷热
［词源］＜古英语swætan(汗,出汗)

all of a sweat
1.一身大汗wet with sweat
She was all of a sweat.她一身大汗。
2.焦急的,害怕的anxious or frightened
She is always all of a sweat before the exam.她临考前总是急得不得了。

no sweat
不费力的〔地〕; 轻易的〔地〕,没什么(used for saying sth will not cause any difficulty)
“Could you manage it?”“No sweat!”“你能对付吗?”“毫无问题!”

He wiped the sweat from his face.他抹去脸上的汗。
The job's quite a sweat; I'm exhausted already.这个工作相当吃力,我已经精疲力竭了。