1.
illegal transaction; black market deal; underground dealing
A transaction conducted secretly and illegally, outside official or regulated channels. Includes black market sales, illicit trading, and under-the-table deals.
闇取引で逮捕された。
He was arrested for illegal transactions.
武器の闇取引が問題になっている。
Illegal arms dealing has become a problem.
戦後の日本では食料品の闇取引が横行していた。
In postwar Japan, black market dealing of food was rampant.
Composed of 闇 (darkness, secrecy) + 取引 (transaction, deal). The prefix 闇 is productive for illegal/underground activities: 闇ルート (illegal channel), 闇金融 (loan sharking), 闇市 (black market). Historically associated with the postwar black market (闇市). In modern usage, appears in news about organized crime, smuggling, and online illegal sales.