1. A casual, relaxed, or non-formal manner of doing something or communicating
They decided to settle the dispute in an informal way without lawyers.
Eles decidiram resolver a disputa de uma maneira informal sem advogados.
2. A style of expression or interaction that is not bound by strict rules or formality
She prefers an informal way of teaching that encourages student participation.
Ela prefere uma forma informal de ensino que encoraja a participação dos alunos.