Dacia, in the era of the Roman Empire, was the land of the Daci or Getae, and corresponds in the main to modern Romania and Moldova. Part of Dacia was, for 165 years, a Roman province (from 106 AD to 271 AD).
The Dacia is a Romanian make of automobile named after that ancient geographic entity. See also Dacia Logan.
Dacia was also a place-name in (medieval) Latin, meaning Denmark, as in "Order of Dacia and Malta " or "Boëthius of Dacia".
There are also three places called Dacia, all in Romania