at one time
used for saying that something was true in the past, but is not now

[TahlilGaran] Dictionary of Contemporary English ▲

in the past at a time before now, especially a long time ago:
In the past, most children didn’t go to school at all.
We had a big argument, but it’s all in the past now.
in those days/in the old days a long time ago in your life, or in your parents’ or grandparents’ lives, when things were different:
£5 was a lot of money in those days.
In the old days, only very rich people had cars.
at one time used for saying that something was true in the past, but is not now:
At one time there were six schools in the village.
I would have agreed with you at one time.
back in the day informal used when you are talking about a time in the past, especially one that you remember as being very good:
I loved Blondie back in the day.
Back in the day, everyone would meet at the boys’ club.

[TahlilGaran] English Thesaurus ▲

at one time
in the past.
At one time this ranch had dozens of cowhands, but now it has fewer than ten.

[TahlilGaran] English Idioms Dictionary ▲

at one time
at a time in the past
At one time the man had no money but now he is very rich.

[TahlilGaran] English Idioms Dictionary ▲

at one time
adv. phr.
1. In the same moment; together.
Let's start the dance again all at one time.
Mr. Reed's bills came all at one time and he could not pay them.
Synonym: AT THE SAME TIME¹.
2. At a certain time in the past; years ago.
At one time people thought that Minnesota was not a good place to live.
At one time most school teachers were men, but today there are more women than men.

[TahlilGaran] English Idioms Dictionary ▲