A victory that takes a devastating toll on the winner is described as what?

A Pyrrhic victory is defined as “a victory that is not worth winning because so much is lost to achieve it.” The word comes from the name of Pyrrhus, an ancient king of Epirus, who suffered heavy losses in defeating the Romans at Asculum in Apulia in 279 B.C.E.

Pyrrhic first came into use as an adjective in the late 17th century, meaning “of, relating to, or resembling that of Pyrrhus.” In its earliest use, it was used in reference to the war waged by the king.

In the early 19th century, Pyrrhic began to be paired with victory, and the two words took on the specific meaning of ‘victory achieved at excessive cost.’