once
adverb uk/wʌns/ us/wʌns/
(ONE TIME)
A2 一次，一回
one single time
I went sailing once, but I didn't like it. 我玩过一次帆船，不过我不喜欢。
We have lunch together once a month. 我们每个月在一起吃一次午餐。
at onceC1 同时
at the same time
They all started talking at once. 他们同时开始讲起话来。
for onceB2 难得一次
used when something happens that does not usually happen
For once, the bus came on time. 难得一次公共汽车准点到达。
just this once 就这一次，仅此一回
used to say that you will only do or request something on this particular occasion
All right, I'll lend you the money - just this once. 好吧，我把钱借给你——仅此一回。
once again(also once more)B1 再次，又一次
again, as has happened before
Once again, racist attacks are increasing across Europe. 种族主义攻势在整个欧洲又开始抬头。
once moreB1 再一次
one more time
I'd like to visit the campus once more before we leave. 我想在我们离开之前再去参观一下大学。
once or twice 几次，一两次
a few times
I've seen him once or twice in town. 我在城里见过他几次。
(every) once in a whileB2 偶尔，间或;有时
sometimes but not often
We meet for lunch once in a while. 我们偶尔见面吃顿午餐。
once and for allC2 彻底了结地；一劳永逸地
completely and in a way that will finally solve a problem
Our intention is to destroy their offensive capability once and for all. 我们的目的是彻底摧毁他们的进攻能力。
once in a lifetime 一生只有一次；千载难逢地；难得地
only likely to happen once in a person's life
An opportunity as good as this arises once in a lifetime. 像这样好的机会可是千载难逢呀。
See also: once-in-a-lifetime
the once UK一次，一回
on a single occasion
I've only played rugby the once, and I never want to play it again. 我只打过一次橄榄球，我再也不想打了。
- More examples
- I go to aerobics once a week.
- I did meet him once and it was an experience I shall never forget.
- The baby only feeds once a night at the moment, thank goodness.
- If I look flustered it's because I'm trying to do so many things at once.
- She's decided to write her memoirs to set the record straight once and for all.
(PAST)
B1 从前，以前;曾经，一度
in the past, but not now
This house once belonged to my grandfather. 这所房子曾属于我的祖父。
Computers are much cheaper nowadays than they once were. 如今计算机要比以前便宜多了。
Once-thriving villages stand deserted and in ruins. 昔日繁荣的村庄今遭废弃，满目疮痍。
- More examples
- Turkey was once an important colonial power.
- England was once a densely wooded country.
- Cancer sufferers no longer face certain death as they once did.
- Shops of this type, once rare, are now numerous.
- An article on this topic would once have been considered off limits.
Idiom
once upon a timeidiom B1 ﹝用于儿童故事的开头﹞从前，很久以前
used at the beginning of children's stories to mean "a long time ago"
Once upon a time there was an ugly duckling. 从前，有一只很丑的鸭子。
（表示对过去的留恋）以往，从前
used when referring to something that happened in the past, especially when showing that you feel sorry that it no longer happens
Once upon a time people knew the difference between right and wrong, but nowadays nobody seems to care. 从前，人们还知道是非曲直，可是如今似乎没人在乎这些了。
once
conjunction uk/wʌns/ us/wʌns/
B2 一…就;一旦…就
as soon as, or from the moment when
Once I've found somewhere to live I'll send you my address. 我一找到住的地方就把地址告诉你。
Remember that you won't be able to cancel the contract once you've signed. 记住一旦你签了字就不能取消合同了。
at onceB1 立刻，马上
immediately
I knew at once that I'd like it here. 我立刻知道我会喜欢这里的。
- More examples
- Decoding the paintings is not difficult once you know what the component parts symbolize.
- You'll feel better once you've got some hot soup down you.
- We can't afford to make any false moves once we're in enemy territory.
- Fourteen miles is further than you'd think once you start to run it.
- My new hiking boots will be great once I've broken them in.
Idioms
all at onceidiom C1 突然，忽然
suddenly and unexpectedly
All at once there was a loud crashing sound. 突然发出哗啦一声巨响。
once bitten, twice shyidiom saying 一次被咬，下次胆小；一朝被蛇咬，十年怕井绳
said when you are frightened to do something again because you had an unpleasant experience doing it the first time