At once
At once adverb - Without delay or hesitation; with no time intervening.
En masse and at once are semantically related. in at the same time topic. In some cases you can use "En masse" instead an adverb phrase "At once".
En masse
Mutual synonyms
Related pairs
- together and at once
- together and en masse
- as a whole and at once
- as a whole and en masse
- concurrently and at once
- concurrently and en masse
- at the same time and at once
- at the same time and en masse
- simultaneously and at once
- simultaneously and en masse
- all at once and at once
- all at once and en masse
- all together and at once
- all together and en masse
Both terms in one sentence
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But before the main characters can figure out where the monsters are coming from and how to effectively kill them en masse, the floodgates open and the city is hit with hundreds of monsters at once.
Source: Alien Invasion -
We Have Reserves: France already was the most populous nation in Europe and the mass Conscription (levée en masse) introduced during the War of the First Coalition enabled its army, despite at time huge numbers of deserters, to take on several major military powers at once.
Cite this Source
En masse and At once. (2016). Retrieved 2026, August 10, from https://thesaurus.plus/related/at_once/en_masse
At once & En masse. N.p., 2016. Web. 10 Aug. 2026. <https://thesaurus.plus/related/at_once/en_masse>.
En masse or At once. 2016. Accessed August 10, 2026. https://thesaurus.plus/related/at_once/en_masse.
Google Ngram Viewer shows how "at once" and "en masse" have occurred on timeline