noun
three-cornered fight; three-way struggle
Used for a conflict or competition involving three parties, such as in politics, sports, or business.
選挙は与党と二大野党による三角闘争となった。
The election turned into a three-cornered fight between the ruling party and the two major opposition parties.
Compound of 三角 (さんかく, 'triangle') and 闘争 (とうそう, 'struggle, fight').