1. A plan, arrangement, or system of questionable legitimacy, legality, or morality
The company was involved in a dubious scheme to avoid paying taxes.
A empresa estava envolvida em um esquema duvidoso para evitar o pagamento de impostos.
2. A suspicious or unreliable arrangement that raises concerns about its authenticity or integrity
He rejected the job offer because it seemed like a dubious scheme.
Ele rejeitou a oferta de emprego porque parecia um esquema duvidoso.