rubicon

English Thesaurus

1. a line that when crossed permits of no return and typically results in irrevocable commitment (noun.cognition)

hypernym	:	contrast, demarcation, dividing line, line,
definition	:	a conceptual separation or distinction (noun.cognition)

2. the boundary in ancient times between Italy and Gaul; Caesar's crossing it with his army in 49 BC was an act of war (noun.location)

instance hypernym	:	bound, boundary, bounds,
definition	:	the line or plane indicating the limit or extent of something (noun.location)