世せ界かい一いち

noun, adverb

best in the world; number one in the world

Used both as a noun and adverbially to describe something as the best or top-ranked globally. Often appears in phrases like 世界一の～ (the world's best ~) or 世界一～ (the most ~ in the world).

• 富ふ士じ山さんは世せ界かい一いち美うつくしい山やまだと思おもう。

  I think Mt. Fuji is the most beautiful mountain in the world.

• 彼かれは世せ界かい一いちのピアニストを