Can you pat your head and rub your belly at once?
He tried to eat four cookies at once.

The [Washington] Post's proprietor through those turbulent Watergate] days, Katharine Graham, held a double place in Washington’s hierarchy: at once regal Georgetown hostess and scrappy newshound, ready to hold the establishment to account.

[T]he book, constructed in short, lucid episodes, can be satisfyingly read as a sequence of provocative talks, at once well informed and vatic.

Tell the doctor to come at once. She is having a baby.

Sparks from the derailed bogie of the train were first noticed by the signalman at Slough West box, who immediately sent to Slough Middle box the "Stop and Examine" signal, followed at once by "Obstruction Danger" when he realised that the coach was derailed.

As soon as Julia returned with a constable, Timothy, who was on the point of exhaustion, prepared to give over to him gratefully. The newcomer turned out to be a powerful youngster, fully trained and eager to help, and he stripped off his tunic at once.

At once

Meaning

Adv

Synonyms