1. Capable of flowing; having the ability to move easily and continuously
The dancer's movements were fluid and graceful.
Os movimentos da dançarina eram fluídos e graciosos.
2. A substance that flows or conforms to the shape of its container, such as liquid or gas
Water is a fluid that fills any container.
A água é um fluído que preenche qualquer recipiente.
3. Smooth and natural in speech, writing, or expression
He speaks fluent Portuguese with a fluid accent.
Ele fala português com um sotaque fluído e natural.