Or for more nuance, we can turn to Wikipedia, which defines habitat this way: "A habitat is an ecological or environmental area that is inhabited by a particular species of animal, plant or other type of organism. It is the natural environment in which an organism lives, or the physical environment that surrounds a species population. A habitat is made up of physical factors such as soil, moisture, range of temperature, and availability of light as well as biotic factors such as the availability of food and the presence of predators. A habitat is not necessarily a geographic area – for a parasitic organism it is the body of its host or even a cell within the host's body."
What SeaWorld provides for its orcas meets neither of those definitions, nor any others. We could fill up the next hundred pages with the names of animals, plants, or other organisms an orca can encounter during its lifetime in the wild and not mention one that it will ever encounter in SeaWorld's tanks. And, far from the space provided being "among the largest in the world today," they are, in fact, a microscopic percentage of the size of habitats available to free, wild orcas: habitats we call the Arctic, Antarctic, Indian, Pacific and Atlantic oceans.