Rubicon vs dividing line

Rubicon and dividing line both are nouns.

Word	Noun	Adjective	Verb	Adverb
Rubicon	Yes	No	No	No
dividing line	Yes	No	No	No

As nouns, dividing line is a hypernym of Rubicon; that is, dividing line is a word with a broader meaning than Rubicon:

Rubicon: a line that when crossed permits of no return and typically results in irrevocable commitment
dividing line: a conceptual separation or distinction

Other hypernyms of Rubicon include contrast, demarcation, line.

Rubicon (noun)	dividing line (noun)
a line that when crossed permits of no return and typically results in irrevocable commitment	a conceptual separation or distinction
the boundary in ancient times between Italy and Gaul; Caesar's crossing it with his army in 49 BC was an act of war