noun
main force; core strength
Refers to the primary military unit, the strongest part of a team, or the most important resource in an organization. Often used in business and sports contexts.
敵の主力部隊が前線に集結した。
The enemy's main force has assembled at the front line.
彼はチームの主力選手として活躍している。
He is playing an active role as a key player on the team.
noun
main effort; primary focus
Used when describing the central activity or emphasis of a plan, project, or policy. Common in phrases like 主力を注ぐ (pour one's main effort into).
会社は新製品の開発に主力を注いでいる。
The company is putting its main effort into developing new products.