1. A secret or undisclosed agreement between two or more parties, often made without the knowledge of others who may be affected by it
The two companies reached a hidden agreement to fix prices and eliminate competition.
As duas empresas chegaram a um acordo secreto para fixar preços e eliminar a concorrência.
2. An implicit or tacit understanding between parties that is not formally documented or publicly acknowledged
There appeared to be a hidden agreement between the politicians to support each other's initiatives.
Parecia haver um acordo secreto entre os políticos para apoiar as iniciativas uns dos outros.