at a time

Prepositional phrase

1. In a single, continuous period of time.
   • He manages to abstain from smoking for weeks at a time, but then gives in and starts again.

   Synonyms:

   in a row, at a stretch

2. Simultaneously at each occurrence (of some action).
   • climb stairs two at a time
   • The Celebrity, by arts unknown, induced Mrs. Judge Short and two other ladies to call at Mohair on a certain afternoon when Mr. Cooke was trying a trotter on the track.[…]Their example was followed by others at a time when the master of Mohair was superintending in person the docking of some...1897 December (indicated as 1898), Winston Churchill, chapter IV, in The Celebrity: An Episode, New York, N.Y.: The Macmillan Company; London: Macmillan & Co., Ltd., →OCLC, pages 58–59

   Synonyms:

   at once

3. Used other than figuratively or idiomatically: see at, a, time.
   • We can't buy a new car at a time when we are already running low on money.