1. A border or boundary between two regions, nations, or territories that changes or moves over time due to political, military, or geographical reasons
The shifting frontier between the two countries reflected decades of territorial disputes and negotiations.
A fronteira móvel entre os dois países refletia décadas de disputas e negociações territoriais.
2. In historical context, especially American history, the advancing edge of settlement and colonization moving westward
The American shifting frontier represented the expansion of European settlements across the continent during the 19th century.
A fronteira móvel americana representava a expansão dos assentamentos europeus através do continente durante o século XIX.
3. A metaphorical boundary that changes in scope, definition, or location within any field or discipline
Technology represents a shifting frontier in modern business competition.
A tecnologia representa uma fronteira móvel na competição comercial moderna.