smart casual
US /ˌsmɑːrt ˈkæʒ.u.əl/
UK /ˌsmɑːrt ˈkæʒ.u.əl/

1.
esporte fino, casual elegante
a dress code that is neat, conventional, and relatively informal, typically for a workplace or social event
:
•
The invitation specified smart casual attire.
O convite especificava traje esporte fino.
•
For the office party, the dress code is smart casual.
Para a festa do escritório, o código de vestimenta é esporte fino.