terra incognita
noun
ter·ra in·cog·ni·ta ˈter-ə-ˌin-ˌkäg-ˈnē-tə 
-in-ˈkäg-nə-tə
-in-ˈkäg-nə-tə plural terrae incognitae ˈter-ˌī-ˌin-ˌkäg-ˈnē-ˌtī
-in-ˈkäg-nə-ˌtī
: unknown territory : an unexplored country or field of knowledge
Did you know?
When Roman mapmakers drew a land area that no one had yet explored, they often labeled it "Terra Incognita"—that is, "Unknown Territory"—and the term continued to be used for centuries afterward. When Columbus and his successors first crossed the Atlantic, they entered upon terra incognita, a land that came to be called the "New World". But the term is just as useful for mental exploration. For most of us, subjects such as particle physics, French 17th-century drama, and soil mechanics are terra incognita, and we can only hope to live long enough to be able to explore some of them someday.
Example Sentences
the terra incognita beyond those mountains
Recent Examples on the Web Detroit isn’t terra incognita for coders and engineers: Ford and GM already employ thousands of developers here, and younger techies are already reshaping the city on the surface. 
Jaclyn Trop, Fortune, 1 June 2022 For most developers and investors—many of whom have made billions over their careers selling houses and condos the old-fashioned way—real estate’s potential crypto new normal is still terra incognita as well. Peter Lane Taylor, Forbes, 7 May 2022 At that time the neighborhood wasn’t even residentially zoned, much less dotted with stores, and both men recall friends shaking their heads at the terra incognita of West 20th Street. Christopher Bollen, Town & Country, 22 Feb. 2022 Even before statehood, in 1850, first Spain and then Mexico tried to govern their terra incognita from thousands of miles away. Los Angeles Times, 21 Sep. 2021 To most of the Taliban, Kabul is terra incognita—a cosmopolitan enclave in an otherwise rural, and deeply traditional, country. Jon Lee Anderson, The New Yorker, 21 Feb. 2022 The acronym stands for Here Be Dragons, an old cartographer’s shorthand for terra incognita. Mark Ellwood, Robb Report, 30 Jan. 2022 Such reticence sounded like terra incognita to Norman Siegel, who led the New York group when Mayor Rudolph W. Giuliani tried to block the Ku Klux Klan from rallying downtown in 1999. New York Times, 6 June 2021 Even before statehood, in 1850, first Spain and then Mexico tried to govern their terra incognita from thousands of miles away. Tribune News Service, oregonlive, 23 Sep. 2021 See More
Jaclyn Trop, Fortune, 1 June 2022 For most developers and investors—many of whom have made billions over their careers selling houses and condos the old-fashioned way—real estate’s potential crypto new normal is still terra incognita as well. Peter Lane Taylor, Forbes, 7 May 2022 At that time the neighborhood wasn’t even residentially zoned, much less dotted with stores, and both men recall friends shaking their heads at the terra incognita of West 20th Street. Christopher Bollen, Town & Country, 22 Feb. 2022 Even before statehood, in 1850, first Spain and then Mexico tried to govern their terra incognita from thousands of miles away. Los Angeles Times, 21 Sep. 2021 To most of the Taliban, Kabul is terra incognita—a cosmopolitan enclave in an otherwise rural, and deeply traditional, country. Jon Lee Anderson, The New Yorker, 21 Feb. 2022 The acronym stands for Here Be Dragons, an old cartographer’s shorthand for terra incognita. Mark Ellwood, Robb Report, 30 Jan. 2022 Such reticence sounded like terra incognita to Norman Siegel, who led the New York group when Mayor Rudolph W. Giuliani tried to block the Ku Klux Klan from rallying downtown in 1999. New York Times, 6 June 2021 Even before statehood, in 1850, first Spain and then Mexico tried to govern their terra incognita from thousands of miles away. Tribune News Service, oregonlive, 23 Sep. 2021 See More Word History
Etymology
Latin
First Known Use
1611, in the meaning defined above