Pyr ‧ rhic vic ‧ to ‧ ry /ˌpɪrɪk ˈvɪkt ə ri/ BrE AmE noun [countable]
[ Date: 1800-1900 ; Origin: Pyrrhus (312?-272BC), Greek king whose army defeated the Romans but had very many killed and wounded ]
a victory in which the person who wins suffers so much that the victory was hardly worth winning