Definition of "at once"

And they all atonce begane to make excuſe. The fyrſt ſayd vnto him: I have bought a ferme / and I muſt nedes goo and ſe it / I praye the have me excuſed.

1526, [William Tyndale, transl.], The Newe Testamẽt […] (Tyndale Bible), [Worms, Germany: Peter Schöffer], Luke xiiij:, folio cj, recto

Those two great champions did attonce pursew / The fearefull damzell with incessany payns [...].

1590, Edmund Spenser, “Book III, Canto IV”, in The Faerie Queene. […], London: […] [John Wolfe] for William Ponsonbie

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.

2013 August 10, Lexington, “Keeping the mighty honest: A new wave of press barons should not allow newspapers to become niche products”, in The Economist‎, volume 408, number 8848

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

2014 September 26, Tom Payne, “Sapiens: a Brief History of Humankind by Yuval Noah Harari, review: 'urgent questions' ”, in The Daily Telegraph (Review)‎

Mr. Cooke at once began a tirade against the residents of Asquith for permitting a sandy and generally disgraceful condition of the roads. So roundly did he vituperate the inn management in particular, and with such a loud flow of words, that I trembled lest he should be heard on the veranda.

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.

One saint's day in mid-term a certain newly appointed suffragan-bishop came to the school chapel, and there preached on “The Inner Life.” He at once secured attention by his informal method, and when presently the coughing of Jarvis […] interrupted the sermon, he altogether captivated his audience with a remark about cough lozenges being cheap and easily procurable.

1918, W[illiam] B[abington] Maxwell, chapter III, in The Mirror and the Lamp, Indianapolis, Ind.: The Bobbs-Merrill Company

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.

1960 March, “Talking of Trains: The Slough derailment”, in Trains Illustrated, page 132

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.

1963, Margery Allingham, chapter 19, in The China Governess‎