1.
defeated nation; loser country (in a war)
A country that has lost a war, especially in the context of international peace settlements and post-war obligations.
戦 (war, battle) + 敗 (defeat) + 国 (country). A formal compound used primarily in historical, political, and journalistic writing.
Usage: More common in writing than in speech. The synonym 敗戦国 is used more frequently; both refer to the same concept.