1. Remote or undeveloped regions at the edge of settled territory, typically characterized by sparse population and limited infrastructure
The frontier lands of the American West attracted settlers seeking new opportunities.
As terras de fronteira do Oeste americano atraíram colonos em busca de novas oportunidades.
2. Territorial areas bordering another country or region, often strategically or politically significant
The frontier lands between the two nations remained disputed for centuries.
As terras de fronteira entre as duas nações permaneceram disputadas por séculos.
3. Areas representing the edge or limits of knowledge, exploration, or development in a particular field
Scientists are exploring the frontier lands of quantum physics.
Os cientistas estão explorando as terras de fronteira da física quântica.