Once
Once conjunction - Just at the moment that.
Usage example: you should have stopped wrestling once you knew someone was getting hurt, not five minutes later
When is a synonym for once in as soon as topic. In some cases you can use "When" instead the word "Once" as a conjunction or an adverb. popular alternative
When
Once is a synonym for when. You can use "Once" instead the word "When" as a conjunction or an adverb. popular alternative
Mutual synonyms
Cite this Source
When and Once. (2016). Retrieved 2026, August 15, from https://thesaurus.plus/related/once/when
Once & When. N.p., 2016. Web. 15 Aug. 2026. <https://thesaurus.plus/related/once/when>.
When or Once. 2016. Accessed August 15, 2026. https://thesaurus.plus/related/once/when.
Google Ngram Viewer shows how "once" and "when" have occurred on timeline