Synonyms of frontier

frontier 1 of 2

noun

ˌfrən-ˈtir 

1

as in border

a region along the dividing line between two countries

the Apaches were once feared on both sides of the U.S.-Mexico frontier

Synonyms & Similar Words

• border
• borderland
• march
• no-man's-land

2

as in countryside

a rural region that forms the edge of the settled or developed part of a country

Alaska has been called America's last frontier

Synonyms & Similar Words

• countryside
• country
• backwater
• backwoods
• hinterland
• backcountry
• bush
• outback
• up-country
• (the) back of beyond
• outlands
• backland(s)
• boondocks
• boonies
• sticks

frontier

2 of 2

adjective

as in marginal

located at or near a border

a frontier town with a reputation for vice and lawlessness

Synonyms & Similar Words

• marginal
• outer
• outside
• borderline
• exterior
• external
• outermost
• outward
• outmost

Antonyms & Near Antonyms

• interior
• inner
• internal
• inside
• inward
• central
• middle
• innermost
• mid
• inmost

Example Sentences

Recent Examples of frontier

Noun

Nvidia and several other tech companies have publicly supported the role of open-weight models as alternatives to the proprietary closed-frontier models trained by companies like OpenAI and Anthropic. — Samuel Axon, ArsTechnica, 27 Aug. 2026

Advertisement Board chair Bret Taylor likens the AI competition to a chessboard whose critical squares include frontier capability, the price and performance of each token, and the products wrapped around the models. — Alex Heath, Time, 26 Aug. 2026

Adjective

That worried Huang, who fears a Chinese rival, and White House officials, who believe Chinese dependence on non-frontier American chips is the best way to ensure a lead in AI. — Charlie Campbell, Time, 11 Dec. 2025