terra incognita

[ ter-uh in-kog-ni-tuh, in-kog-nee-; Latin ter-rah in-kawg-ni-tah ]
/ ˈtɛr ə ɪnˈkɒg nɪ tə, ˌɪn kɒgˈni-; Latin ˈtɛr rɑ ɪnˈkɔg nɪ tɑ /

noun

an unknown or unexplored land, region, or subject.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for terra incognita

terra incognita

/ Latin (ˈtɛrə ɪnˈkɒɡnɪtə) /

noun

an unexplored or unknown land, region, or area for study
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012