noun

frontier

fruhn-TEER/frʌnˈtɪr/

The outermost boundary of explored or settled territory.

A small cabin and cultivated patch mark the frontier beside the forest.

A small cabin and cultivated patch stand at the edge of a much larger uncultivated forest; focus on border between settled ground and undeveloped land, no claims of uninhabited or conquered territory.

Etymology

frontierOld Frenchboundary; military front rank

Old French frontiere named a country's boundary or an army's front rank. The boundary idea was applied to the outer edge of settled territory, giving the sense of a border region beyond settlement.

In context

Kings and Generals10:30

nomadic and semi-nomadic peoples along the frontier between the steppe and the Jin Dynasty, who paid tribute to the Jin and patrolled the border.

The Lost History of Genghis Khan - Mongol History DOCUMENTARY

More examples

As new towns grew, the frontier shifted westward.
The map shows the frontier of the explored region.
Supplies reach the remote frontier by river.

Forms

frontier · frontiers

Similar words

boundary: Names any dividing line, not specifically the limit of settlement.
border: Usually separates political territories rather than marking exploration's outer limit.
edge: Names an outer margin without suggesting settlement or exploration.