優勢|ゆうせいyuusei[0]heiban (flat)

1. noun, na-adjectivesuperiority; superior power; predominance; preponderance
   人類じんるいは地球ちきゅう上じょうで最もっとも優勢ゆうせいである。↗

   The human race is dominant on earth.

• Synonym優越ゆうえつWrittenWritten/formal prose. Being superior in ability, performance and the like, as in 「優越感」; 優勢 is about holding the upper hand in a situation.
• Synonym優位ゆういNeutralNeutral. Being in an advantageous position, as in 「優位に立つ」. Close to 優勢 but leans toward standing or status rather than the flow of a contest.
• Synonym優越性ゆうえつせいWrittenWritten/formal prose. Superiority as an abstract quality; 優勢 points to a momentary state of affairs.
• Synonym優位性ゆういせいWrittenWritten/formal prose. An advantageous position, often in business competitiveness; 優勢 is about the situation at hand.
• Related支配的しはいてきWrittenWritten/formal prose. Dominant, holding sway, as in 「支配的な意見」; leans toward predominance rather than an edge in a contest.
• Antonym劣勢れっせいNeutralNeutral. The opposite of 優勢: being at a disadvantage, as in 「劣勢を挽回する」.

Use 「優勢」 for holding the upper hand in a situation or match, as in 「優勢を保つ」「優勢勝ち」. For an advantageous position say 「優位」, for being superior in ability 「優越」; 「優越性」「優位性」 name abstract superiority (written), 「支配的」 dominance, and 「劣勢」 is the opposite.

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

1. 勢いきおい・形勢けいせいが他ほかよりも良よいこと。優位ゆうい。