1. An unlawful or illegal activity, often involving criminal conduct, smuggling, or unauthorized business practices
The police discovered an illegal operation running counterfeit currency in the warehouse.
A polícia descobriu uma operação ilícita de fabricação de moeda falsa no armazém.
2. A clandestine business venture that violates laws or regulations
Drug trafficking rings often operate as illegal operations across borders.
Redes de tráfico de drogas frequentemente funcionam como operações ilícitas além das fronteiras.