at one time

Prepositional phrase

formerly / simultaneously, at once.

Japanese Meaning

かつては / 同時に / 一度に

This building, at one time, housed a bustling theater, but now it's a bookstore.

この建物はかつて賑やかな劇場だったが、今は本屋になっている。

Sense（1）

formerly

At one time, I could walk ten miles in a day, but I can't any longer.

Sense（2）

simultaneously, at once.

A bigamist has two spouses at one time.