(idiomatic) To make an irreversible decision or to take an action with consequences.

Possessing a red complexion; ruddy.

Alternative letter-case form of rubicon (“a limit that when exceeded, or an action that when taken, cannot be reversed; especially in bezique and piquet: a score which, if not achieved by a losing player, increases the player's penalty”)

(historical) A small river in northeastern Italy which flowed into the Adriatic Sea marking the boundary between the Roman province of Gaul and the Roman heartland. Its crossing by Julius Caesar in 49 B.C.E. began a civil war.

(rare) reddish, ruddy, inflamed

(pharmacology) Used to form names of daunorubicin derivatives used as antineoplastics.

(mineralogy) Alternative form of rubicelle

plural of rubicel

simple past tense and past participle of rubicon

present participle of rubicon