___ incognita (unexplored area)

TERRA

Think of the Latin word for "earth" or "land," often used in historical maps to mark unknown regions. This term also appears in the name of a famous Australian exploration initiative.

This clue plays on the Latin phrase terra incognita, which literally means "unknown land" and was historically used on maps to mark unexplored regions. The blank asks for the first word of that phrase, which is terra—Latin for "earth" or "land." It’s a straightforward fill-in-the-blank, but knowing the phrase’s origin helps, as it’s still used today to describe unfamiliar territory in both literal and metaphorical senses.