ライバルraibaru

1. nounrival; competitor; competition
   彼かれは自分じぶんのライバルをひどくこきおろした。↗

   He criticized his rival severely.

• Synonym敵てきNeutralAn opponent in a fight or match, and also an enemy or foe, as in 「目の敵」 and 「商売敵」; 「ライバル」 generally carries no sense of hatred.
• Synonym競合者きょうごうしゃWrittenWritten/formal prose for someone competing for the same goal or interests, mostly in business; 「ライバル」 is more colloquial and often carries a sense of mutual rivalry.
• Synonym競争相手きょうそうあいてNeutralA neutral, objective term for a competitor; you can usually swap it for 「ライバル」, but 「ライバル」 often adds a nuance of a worthy opponent or nemesis.
• Related敵かたきNeutralAn opponent in a fight or match, and also an enemy or foe, as in 「目の敵」 and 「商売敵」; 「ライバル」 generally carries no sense of hatred.
• Related挑戦者ちょうせんしゃNeutralSomeone who issues a challenge, or who has earned the right to face a champion; 「ライバル」 describes a mutual rivalry with no attacker-defender split.
• Related対戦相手たいせんあいてNeutralThe side you actually face in a given match or game; 「ライバル」 suggests an ongoing rivalry and is not limited to a single contest.
• Antonym味方みかたNeutralA companion or supporter on your side; it is the antonym of 「ライバル」 in terms of which side someone stands on.

For a rival in general, use 「ライバル」, which often implies a worthy opponent; for an objective description pick 「競争相手」, for the opposing side in a match 「対戦相手」, and with hostility 「敵」; the opposite is 「味方」.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. 競争相手きょうそうあいて、好敵手こうてきしゅ。