The Enterprise-class was a type of aircraft carrier aquatic vessel in use by the United States Navy on the planet Earth in the 20th century. The USS George Washington and USS Theodore Roosevelt were Enterprise-class carriers. (TNG novel: Ghost Ship)
In Ghost Ship, the George Washington is described as belonging to the Enterprise-class, despite the fact that the real-life vessel was a ship of the Nimitz-class. The George Washington was not yet in service at the time of the book's writing in 1987. The "Enterprise-class" is an uncertain designation, seeing as the prototype USS Enterprise (CVN-65) led the way for a generation of nuclear powered aircraft carriers, of which the Washington is a part, even though, in the strictest definition, Enterprise is in a class by herself since no other vessels were constructed to her exact specification.