adv. 1 once upon a time, formerly, (at) one time, on a former occasion, previously, before, in days gone by, in olden days, in the (good) old days, long ago, some time ago, years or ages or aeons ago, in days of yore Your hair is as long as mine once was He was once a famous film star. That once revered leader has fallen. 2 one time, on one occasion, a single time He has visited his family only once in all these years 3 once and for all. finally, positively, definitely, decidedly, conclusively, for good We must settle the itinerary once and for all before we can make the bookings 4 once in a while. occasionally, (every) now and then, now and again, at times, sometimes, periodically, from time to time, at intervals, sporadically We go to the theatre once in a while
conj. 5 (if) ever, as soon as, at any time Once the bus comes, you'd best get on it straight away
n. 6 at once. a immediately, straight away, right away, directly, without delay, promptly, instantly, post-haste; in a wink, in the twinkling of an eye, in a minute or moment or second or split second, in no time (at all), before you can turn around, before you can say 'Jack Robinson', in a trice, Colloq in a jiffy, in two shakes of a lamb's tail Watson, come here at once I'll be there at once. b together, at the same time, simultaneously, at a stroke, in the same instant, in the same breath, Colloq at one go, at a go, in one go You cannot be in two places at once