noun
signs of defeat; adverse situation
Refers to a situation where defeat seems imminent or the tide has turned against one. Often used in competitive or conflict contexts.
試合の後半、チームは敗勢を挽回しようと必死だった。
In the second half, the team desperately tried to recover from the adverse situation.
敗勢が濃厚になった時点で、監督は選手を交代させた。
When signs of defeat became clear, the coach substituted players.
Compound of 敗 (hai, 'defeat') and 勢 (sei, 'force, momentum, situation'). The exact historical derivation is uncertain, but the word follows standard Sino-Japanese compounding patterns.