In "The Canterville Ghost," why was the mansion called Canterville Chase?

A chase is a hunting or game preserve. Canterville Hall or Canterville Chase is called a chase because it was once, and probably still is, a place where upper-class people would gather to hunt. It would have been stocked with game, such as pheasants or deer, and a popular activity would have been to go out on horseback to shoot these animals. A reference to the hall as a hunting lodge can be seen in the "faded green tapestry" that Virginia sees, "broidered" with "little huntsmen."

We know the hall is surrounded by grounds because the men go on horseback to search the grounds (the Chase) and the adjoining commons when Virginia is missing. We might note too that the verb chase, as in chasing an animal, probably led to hunting grounds being called chases, as they are, in fact, places where you chase animals. It is possible too that Wilde uses the term "chase" because the Ghost ends up feeling hunted or chased by the Otis family, especially the twin boys: he has become the "game."