At once
At once adverb - Without delay or hesitation; with no time intervening.
On a sudden and at once are semantically related. In some cases you can use "On a sudden" instead an adverb phrase "At once".
On a sudden
At once and on a sudden are semantically related. You can use "At once" instead an adverb phrase "On a sudden".
Mutual synonyms
Cite this Source
On a sudden and At once. (2016). Retrieved 2026, August 01, from https://thesaurus.plus/related/at_once/on_a_sudden
At once & On a sudden. N.p., 2016. Web. 01 Aug. 2026. <https://thesaurus.plus/related/at_once/on_a_sudden>.
On a sudden or At once. 2016. Accessed August 01, 2026. https://thesaurus.plus/related/at_once/on_a_sudden.
