Pyrrhic - a metrical foot of two short unaccented syllables which is common in classical poetry. Most often, it is used as an adjective, applying to a victory won at too great a cost. It also means an ancient Greek warlike dance in which the motions of combat were imitated, much like Native North American war-dances.
The term is from the Greek purrhikhios derived from purrhikhe which is said to be named for Purrhikhos, the inventor of a war-dance of the ancient Greeks.
Pyrrhus, King of Epirus, won a notable battle over the Romans at Asculum in the Third Century B.C. but lost so many men that he allegedly said, “One more such victory and we are lost.”