1. Firm, stable earth or land that can safely support weight and construction
The builders confirmed they had solid ground for the foundation.
Os construtores confirmaram que tinham terreno sólido para a fundação.
2. Figuratively, a firm basis or foundation for an argument, plan, or position
Their proposal stands on solid ground with extensive research.
A proposta deles está em terreno sólido com pesquisa extensiva.