noun
prostitution ring
Refers to an organized group or network that manages or facilitates prostitution, often with criminal connotations.
警察は大規模な売春組織を摘発した。
The police busted a large-scale prostitution ring.
売春 means 'prostitution' as an act or practice, while 売春組織 refers specifically to the organized group or network behind it.
Compound of 売春 (prostitution) + 組織 (organization).