1. The floor of a building that is at street level or ground level, typically the lowest floor of a building
The shop is located on the ground-floor of the shopping center.
A loja fica localizada no rés-do-chão do centro comercial.
2. An advantageous position or early opportunity in a venture or enterprise
He got in on the ground-floor of the startup company.
Ele entrou no início da empresa de tecnologia.