強敵

1. Origins, structure, and basic meaning

• Structure: 強敵 (きょうてき) is a noun for a formidable enemy, opponent, or rival.
• Basic usage: It applies to an actual competitor and figuratively to a difficult problem treated as an opponent.
  • 決勝で当たる相手は、今までにない強敵です。 — Our opponent in the final is stronger than anyone we have faced.
  • 難しい数学の問題を強敵に見立てて挑みました。 — I treated the difficult math problem like a formidable rival.

2. Common pitfalls and similar expressions

• Enemy and demanding challenge
  • 敵 broadly means an enemy, while 強敵 stresses formidable strength. With に見立てる, it can figuratively cast a problem as a rival.