Synonyms of once in English:

once


See definition of once

adverb

1‘I saw him only once’

SYNONYMS

on one occasion, one time, one single time

ANTONYMS

twice, many times

2‘he did not once help’

SYNONYMS

ever, at any time, on any occasion, at all, under any circumstances, on any account, in a million years

3‘they were friends once’

SYNONYMS

formerly, previously, in the past, at one time, at one point, once upon a time, on a former occasion, on one occasion, one time, in one case, time was when, in days gone by, in times gone by, back in the day, in times past, in the old days, in the good old days, long ago

archaic sometime, erst, erstwhile, whilom

literary in days of yore, in times of yore, of yore

ANTONYMS

now


conjunction

1‘he'll be all right once she's gone’

SYNONYMS

as soon as, when, after, immediately after, the instant, the minute, the moment, the second

British informal immediately


Phrases

    at once

      1‘you must leave at once’

      SYNONYMS

      immediately, right away, right now, this instant, this minute, this moment, this second, now, straight away, instantly, instantaneously, directly, suddenly, abruptly, summarily, forthwith, promptly, without delay, without hesitation, without further ado

      quickly, as fast as possible, as soon as possible, fast, speedily, with all speed

      informal

      like a shot, in a flash, like a flash, before you can say Jack Robinson, in two shakes, in two shakes of a lamb's tail

      ANTONYMS

      later, in due course

      2‘all the guests arrived at once’

      SYNONYMS

      at the same time, at one and the same time, at the same instant, at the same moment, together, all together, simultaneously

      as a group, in unison, in concert, in chorus

      ANTONYMS

      singly, in dribs and drabs

    once and for all

      1‘you must decide once and for all’

      SYNONYMS

      conclusively, decisively, finally, positively, absolutely, determinedly, definitely, definitively, irrevocably

      2‘he has gone once and for all’

      SYNONYMS

      for good, for always, forever, permanently, finally, in perpetuity

      informal

      for keeps

    once in a while

      ‘once in a while a car went past’

      SYNONYMS

      occasionally, from time to time, now and again, now and then, every now and again, every now and then, every so often, every once in a while, on occasion, on occasions, on the odd occasion, at times, sometimes, off and on, at intervals, periodically, sporadically, spasmodically, erratically, irregularly, intermittently, by fits and starts, in fits and starts, fitfully, discontinuously, piecemeal

      rare

      interruptedly