cross the Rubicon
In real, traceable use. Part of the curated seed collection; community review is coming.
Meaning · English
Take an irrevocable step.
Where it’s used:
Used
Widespread English
Examples
Instead, regardless of whether it actually pulls back its troops to South ~ Ossetia and Abkhazia, Russia has crossed the Rubicon, making this a watershed moment in the West ’s post - Cold ~ War relations with Russia.
Though he showed no very clear signs that he realized it, the Tsar had crossed the Rubicon, carrying the nobility with him.
British National Corpus sentence via the MAGPIE corpus (CC BY 4.0, retrieved 2026-07-30)
Sources & notes
Listed in Wiktionary’s “English idioms” category (retrieved 2026-07-29); definition pending editorial review. Figurative class: Metaphor (PIE-English corpus, CC BY 4.0, retrieved 2026-07-31).
Common questions
What does “cross the Rubicon” mean?
Take an irrevocable step.
Is “cross the Rubicon” formal or informal?
No register label has been reviewed yet — treat it as neutral and check the usage notes above.