界(かい)

かい
noun, suffix
world; realm; sphere
1. world; realm; sphere; circle
A specific field, domain, or community of people sharing a common profession, interest, or characteristic. Often used as a suffix.
彼女(かのじょ)は芸能(げいのう)界(かい)で活躍(かつやく)している。
She is active in the entertainment world.
政治(せいじ)界(かい)では大(おお)きな変化(へんか)があった。
There was a big change in the political world.
学会(がっかい)は学術(がくじゅつ)界(かい)の重要(じゅうよう)な集(あつ)まりだ。
Academic conferences are important gatherings in the scholarly world.

界(かい) is primarily used as a suffix meaning "world" or "realm" attached to a field, profession, or domain. It is rarely used as a standalone word.

COMMON COMPOUNDS:

  • 芸能(げいのう)界(かい): entertainment industry
  • 政治(せいじ)界(かい): political world
  • 財(ざい)界(かい): financial/business world
  • 学(がっ)界(かい): academic world
  • スポーツ界(かい): sports world
  • 業(ぎょう)界(かい): industry (specific business sector)

USAGE:
The pattern is [field]界(かい) to refer to the community of people and institutions in that field. It can also mean "sphere" in a more abstract or scientific sense, as in 世界(せかい) (the world).

REGISTER:
Common in news reporting and formal writing when discussing professional fields.

general
Added 2026.2.3 11:58 · Revised 2026.3.26 22:07
09500/09651_kai