If something happens once, it happens one time only.
I met Wilma once, briefly.
Since that evening I haven't once slept through the night.
Mary had only been to Manchester once before.
Once is also a pronoun.
'Have they been to visit you yet?'—'Just the once, yeah.'
Listen to us, if only this once.
2. adverb
You use once with 'a' and words like 'day', 'week', and 'month' to indicate that something happens regularly, one time in each day, week, or month.
Lung cells die and are replaced about once a week.
We arranged a special social event once a year to which we invited our major customers.
3. adverb [ADVevery n, ADVevery num n]
You use once with 'every' and words like 'day', 'week', and 'year' to indicate that somethinghappens a specified number of times and on a regular basis.
The patient was seen for follow-up visits once every three months.
My daughter comes to visit me once every fortnight.
4. adverb [ADVERB with verb, ADV with be]
If something was once true, it was true at some time in the past, but is no longer true.
The culture minister once ran a theatre.
I lived there once myself, before I got married.
The house where she lives was once the village post office.
My memory isn't as good as it once was.
...an undulating park, once lovely but now ruined by new buildings.
Synonyms: at one time, in the past, previously, formerly More Synonyms of once
5. adverb [ADVERB with verb]
If someone once did something, they did it at some time in the past.
I once went camping at Lake Darling with a friend.
We once walked across London at two in the morning.
Diana had taken that path once.
6. conjunction
If something happens once another thing has happened, it happens immediately afterwards.
The decision had taken about 10 seconds once he'd read a market research study.
Once customers come to rely on these systems they almost never take their businesselsewhere.
Once inside her apartment she felt an urge to brush her teeth.
Synonyms: as soon as, when, after, the moment More Synonyms of once
7.
See all at once
8.
See at once
9.
See at once/all at once
10.
See for once
11.
See once again
12.
See once and for all
13.
See once in a while
14.
See once or twice
15.
See once upon a time
16. once in a blue moon
More Synonyms of once
once in British English
(wʌns)
adverb
1.
one time; on one occasion or in one case
2.
at some past time; formerly
I could speak French once
3.
by one step or degree (of relationship)
a cousin once removed
4. (in conditional clauses, negatives, etc)
ever; at all
if you once forget it
5.
multiplied by one
6. once and away
7. once and for all
8. once in a while
9. once or twice
10. once upon a time
conjunction
11. (subordinating)
as soon as; if ever or whenever
once you begin, you'll enjoy it
noun
12.
one occasion or case
you may do it, this once
13. all at once
14. at once
15. for once
Word origin
C12 ones, ānes, adverbial genitive of on, ānone
once in American English
(wʌns)
adverb
1.
one time; one time only
to eat once a day
2.
at any time; at all; ever
she'll succeed if once given a chance
3.
at some time in the past; formerly
a once famous man
4.
by one degree or grade
a cousin once removed
conjunction
5.
as soon as; if ever; whenever
once he has made his point, he will be quiet
adjective
6.
former; quondam
noun
7.
one time
go this once
Idioms:
all at once
at once
for once
once and again
once (and) for all
once in a while
once or twice
once upon a time
Word origin
ME ones, gen. of on, one
Examples of 'once' in a sentence
once
There is no talk about what happens once consent has been granted.
Times, Sunday Times (2016)
Cash once set aside surfaces to solve a family mystery.
The Sun (2016)
They cite these as further evidence that life may have once thrived around these hot springs.
Smithsonian Mag (2017)
This season he has been cautioned just once.
Times, Sunday Times (2016)
We are human beings and we can do two things at once.
The Sun (2016)
She might have been lost to the game once upon a time.
The Sun (2017)
Once inside, viewers of the show have been voting for them to take on all manner of creepy paranormal activities.
The Sun (2016)
A friend introduced him to a woman he likes very much; they meet as often as once a week.
Times, Sunday Times (2016)
As a portrait in music of a family's struggle to come to terms with loss, it is at once compelling and almost unbearable.
Times, Sunday Times (2016)
Once again we played not so badly.
The Sun (2016)
Now she determined once again to set out without him.
Linda Colley The Ordeal of Elizabeth Marsh: A Woman in World History (2007)
Perhaps his help had been refused once too often.
Aldiss, Brian Somewhere East of Life (1994)
Plus it is cheaper for firms to offer you all three and bill you just once.
The Sun (2012)
We have to wait to see the position of this club once things are sorted.
The Sun (2012)
Some of the younger pilots discovered almost at once that they were good at air fighting.
Patrick Bishop FIGHTER BOYS: Saving Britain 1940 (2003)
We did this and only got a home police visit once.
The Sun (2012)
Coupons can only be redeemed once and only one coupon is valid per transaction.
The Sun (2011)
You may use it once in a blue moon.
Times, Sunday Times (2007)
We needed to take control once again.
The Sun (2009)
Once or twice he showed us up badly when we had people over.
The Sun (2008)
What happened to his once blazing star?
Times, Sunday Times (2008)
Prizes come on average once or twice a week.
Times, Sunday Times (2007)
Seal once cold and then store.
Times, Sunday Times (2007)
This happens about once a month during the summer and increasingly so as the weather gets colder or the battery loses charge.
Times, Sunday Times (2012)
He did not once complain about the pain he was in or the fact that his life would undoubtedly be cut short.
The Sun (2014)
In other languages
once
British English: once /wʌns/ ADVERB
If something happens once, it happens one time only.
I met her once, at a party.
American English: once
Arabic: مَرَةٌ
Brazilian Portuguese: uma vez
Chinese: 一次
Croatian: jednom
Czech: jednou
Danish: en gang
Dutch: eens
European Spanish: una vez
Finnish: kerran
French: une fois
German: einmal
Greek: άπαξ
Italian: una volta
Japanese: 一度
Korean: 한 번
Norwegian: en gang
Polish: raz
European Portuguese: uma vez
Romanian: o dată
Russian: однократно
Latin American Spanish: una vez
Swedish: en gång
Thai: ครั้งหนึ่ง
Turkish: bir seferinde
Ukrainian: один раз
Vietnamese: một lần
Chinese translation of 'once'
once
(wʌns)
adv
(= one time only) 一次 (yīcì)
(= at one time) 曾经(經) (céngjīng)
⇒ Texas was once ruled by Mexico.得克萨斯州曾经受墨西哥管辖。 (Dékèsàsī zhōu céngjīng shòu Mòxīgē guǎnxiá.)
(= on one occasion) 有一次 (yǒu yī cì)
⇒ I went to Portugal once.我去过一次葡萄牙。 (Wǒ qùguo yī cì Pútáoyá.)
conj
(= as soon as) 一旦 (yīdàn)
at once (= immediately) 立刻 (lìkè) (= simultaneously) 同时(時) (tóngshí)
once a or every month每月一次 (měi yuè yī cì)
once more or again再一次 (zài yī cì)
once and for all一劳(勞)永逸地 (yī láo yǒng yì de)
once upon a time (= in stories) 很久以前 (hěnjiǔ yǐqián) (= in the past) 从(從)前 (cóngqián)
once in a while偶尔(爾) (ǒu'ěr)
all at once (= suddenly) 突然 (tūrán)
for once就这(這)一次 (jiù zhè yī cì)
just this once (inf) 就这(這)一次 (jiù zhè yī cì)
once or twice (= a few times) 一两(兩)次 (yī liǎng cì)
All related terms of 'once'
at once
( immediately ) 立刻 lìkè
for once
就这(這)一次 jiù zhè yī cì
once more
再一次 zài yīcì
all at once
( suddenly ) 突然 tūrán
once or twice
( a few times ) 一两(兩)次 yī liǎng cì
just this once
( inf ) 就这(這)一次 jiù zhè yī cì
more than once
不止一次 bù zhǐ yī cì
once and for all
一劳(勞)永逸地 yī láo yǒng yì de
once in a while
偶尔(爾) ǒu'ěr
once upon a time
( in stories ) 很久以前 hěnjiǔ yǐqián
once more or again
再一次 zài yī cì
once/twice a week
一周(週)一次/两(兩)次 yī zhōu yī cì/liǎng cì
once in a blue moon
千载(載)难(難)逢 qiān zǎi nán féng ⇒ Once in a blue moon you get some problems. → 偶尔你也碰到一些麻烦。 Ǒu'er nǐ yě pèngdào yīxiē máfan.
once a or every month
每月一次 měi yuè yī cì
once you get the idea
一旦你明白了 yīdàn nǐ míngbai le
my first cousin once removed
我堂亲(親)/表亲(親)的子女 wǒ tángqīn/biǎoqīn de zǐnǚ
(only) once in a blue moon
(仅(僅)是)难(難)得的一次 (jǐn shì) nándé de yī cì
1 (adverb)
Definition
one time
I only met her once, very briefly.
Synonyms
on one occasion
one time
one single time
2 (adverb)
Definition
at some past time, but no longer
I lived there once, before I was married.
Synonyms
at one time
At one time, 400 people lived in the village.
in the past
previously
Previously she had no time to work in her own garden.
formerly
He had formerly been in the Navy.
long ago
in the old days
once upon a time
in times past
in times gone by
(conjunction)
Definition
as soon as
Once she got inside the house, she slammed the door.
Synonyms
as soon as
when
after
the moment
immediately
the instant
phrases
See all at once
See at once
idioms
See once and for all
See once in a while
Additional synonyms
in the sense of formerly
Definition
in the past
He had formerly been in the Navy.
Synonyms
previously,
earlier,
in the past,
at one time,
before,
lately,
once,
already,
heretofore,
aforetime (archaic)
in the sense of previously
Previously she had no time to work in her own garden.
Synonyms
before,
earlier,
once,
in the past,
formerly,
back then,
until now,
at one time,
hitherto (formal),
beforehand,
a while ago,
heretofore,
in days or years gone by
Synonyms of 'once'
once
Explore 'once' in the dictionary
All related terms of 'once'
at once
immediately, now, right now, straight away, directly
all at once
suddenly, unexpectedly, abruptly, all of a sudden, out of the blue
once and for all
for the last time, finally, completely, for good, positively
once in a while
occasionally, sometimes, at times, from time to time, on and off
once in a blue moon
rarely, almost never, very seldom, hardly ever, scarcely ever