闇やみ価か格かく協きょう定てい

• 価か格かく協きょう定てい

  A price-fixing agreement in general, not necessarily illegal. 闇価格協定 specifically implies an illegal, secret agreement.

• カルテル

  A cartel; often used in the same context, but 闇価格協定 emphasizes the illegal price-fixing aspect.

Compound of 闇 (yami, 'darkness; illegal') + 価格 (kakaku, 'price') + 協定 (kyōtei, 'agreement'). The exact historical derivation is uncertain; the term likely emerged in economic or legal discourse.