Origin: French suffix -ier
Frontier has 7 different meanings across 2 categories:
a wilderness at the edge of a settled area of a country
"the individualism of the frontier in Andrew Jackson's day"
an international boundary or the area (often fortified) immediately inside the boundary
"The explorers ventured across the frontier, where they encountered both the international boundary and the heavily fortified settlements just beyond it."
an undeveloped field of study; a topic inviting research and development
"he worked at the frontier of brain science"
The part of a country which borders or faces another country or unsettled region
"The explorers traveled west to map the frontier where the settled farms met the vast, untamed wilderness."
In plain English: A frontier is an area at the edge of where people currently live and explore new lands beyond it.
"The remote village lies on the frontier between two different countries."
Usage: Use "frontier" to describe an unexplored boundary between nations or a remote, undeveloped area rather than a simple city edge. When referring specifically to the line where two countries meet, consider using "border" for greater precision in everyday contexts.
To live as pioneers on frontier territory.
"The settlers decided to move west to live as pioneers on frontier territory where no roads had yet been built."
In plain English: To frontier something means to push it forward into new territory, though this is not actually used as a verb and people usually just say they are exploring or expanding instead.
"The company plans to frontier new markets by next quarter."
Lying on the exterior part; bordering; coterminous.
"The new settlement was established on a frontier where the dense forest ended and open plains began."
In plain English: Frontier describes something that is new, unexplored, and at the very edge of what people currently know or can do.
"The company launched several frontier technologies to stay ahead in the market."
An unincorporated community in Koochiching, Minnesota.
"The village of Frontier is an unincorporated community located in Koochiching County, Minnesota."
The word frontier entered English via the phrase de la frontière, which literally meant "from the border." It originally referred to a boundary line or edge before evolving into its modern sense of an undeveloped region beyond settled areas.