1. An agreement or understanding between parties that is not formally documented or legally binding, often based on mutual trust and verbal communication
They reached an informal agreement to split the project costs.
Eles chegaram a um acordo informal para dividir os custos do projeto.
2. A casual arrangement or understanding without official procedures or written contracts
The neighbors made an informal agreement about parking spaces.
Os vizinhos fizeram um acordo informal sobre os espaços de estacionamento.