Rubicon

Origin

The noun is derived from the phrase cross the Rubicon (“to make an irreversible decision or to take an action with consequences”). Julius Caesar’s crossing of the Rubicon, a small river in northeastern Italy, on 10 January 49 B.C.E., indicated his intention to start a civil war with Pompey. Rubicon is derived from Latin Rubicō, Rubicōn (“the Rubicon”), possibly from rubeus (“red, reddish”), from rubeō (“to be red”), ultimately from Proto-Indo-European *h₁rewdʰ- (“red”), an allusion to the colour of the river caused by mud deposits. The verb is derived from the noun.