1. The process of adopting a more relaxed, informal, or less serious demeanor or approach
The tone of the conversation was becoming casual after a few drinks.
O tom da conversa estava se tornando casual depois de algumas bebidas.
2. Transitioning a formal relationship into a more relaxed, non-committed arrangement
They decided their relationship was becoming casual rather than serious.
Eles decidiram que seu relacionamento estava se tornando casual em vez de sério.
3. Adopting a more informal style of dress or behavior
The dress code was becoming casual as the company relaxed its policies.
O código de vestuário estava se tornando casual conforme a empresa relaxava suas políticas.