Rubicon

[ roo-bi-kon ]
/ ˈru bɪˌkɒn /
|

noun

a river in N Italy flowing E into the Adriatic. 15 miles (24 km) long: in crossing this ancient boundary between Cisalpine Gaul and Italy, to march against Pompey in 49 b.c., Julius Caesar made a major military commitment.

Idioms

    cross/pass the Rubicon, to take a decisive, irrevocable step: Our entry into the war made us cross the Rubicon and abandon isolationism forever.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for rubicon

British Dictionary definitions for rubicon

Rubicon

/ (ˈruːbɪkən) /

noun

a stream in N Italy: in ancient times the boundary between Italy and Cisalpine Gaul. By leading his army across it and marching on Rome in 49 bc, Julius Caesar broke the law that a general might not lead an army out of the province to which he was posted and so committed himself to civil war with the senatorial party
(sometimes not capital) a point of no return
a penalty in piquet by which the score of a player who fails to reach 100 points in six hands is added to his opponent's
cross the Rubicon or pass the Rubicon to commit oneself irrevocably to some course of action

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Culture definitions for rubicon

Rubicon

[ (rooh-bi-kon) ]

A river in northern Italy that Julius Caesar crossed with his army, in violation of the orders of the leaders in Rome, who feared his power. A civil war followed, in which Caesar emerged as ruler of Rome. Caesar is supposed to have said, “The die is cast” (referring to a roll of dice), as he crossed the river.


Note

“Crossing the Rubicon” is a general expression for taking a dangerous, decisive, and irreversible step.
The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Idioms and Phrases with rubicon

Rubicon

see cross the rubicon.


The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.