Ru·bi·con (r
b
-k
n
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b-kn)| Noun | 1. |  Rubicon - the boundary in ancient times between Italy and Gaul; Caesar's crossing it with his army in 49 BC was an act of war. |
| 2. | Rubicon - a line that when crossed permits of no return and typically results in irrevocable commitment; a conceptual separation or distinction; "there is a narrow line between sanity and insanity" |
