Refers to an illegal market, especially those that flourished in post-war Japan.
戦後、闇市で食料を手に入れた。
After the war, people got food on the black market.
black market
Standard kanji spelling.
Katakana spelling sometimes used for emphasis or in historical contexts.
Compound of 闇 (yami, 'darkness; illegal') and 市 (ichi, 'market').