A Pyrrhic victory ( PIRR-ik) is a victory that inflicts such a devastating toll on the victor that it is tantamount to defeat. Such a victory negates any true sense of achievement or damages long-term progress.
The phrase originates from a quote from Pyrrhus of Epirus, whose triumph against the Romans in the Battle of Asculum in 279 BC destroyed much of his forces, forcing the end of his campaign.
Etymology
A "Pyrrhic victory" is named after King Pyrrhus of Epirus, whose army suffered irreplaceable casualties in defeating the Romans at the Battle of Heraclea in 280 BC and the Battle of Asculum in 279 BC, during the Pyrrhic War. After the latter battle, Plutarch relates in a report by Dionysius:
The armies separated; and, it is said, Pyrrhus replied to one that gave him joy of his victory that one other such victory would utterly undo him. For he had lost a great part of the forces he brought with him, and almost all his particular friends and principal commanders; there were no others there to make...