Plain English Meaning
A navigation standard that says the aircraft must stay within 2 nautical miles of the intended track at least 95 percent of the time. The '2' is the allowed accuracy in nautical miles.
Full Definition
An area navigation specification requiring the aircraft's lateral navigation system to maintain a total system error of no more than 2 nautical miles for at least 95 percent of the flight time. RNAV 2 applies primarily to en route operations in the continental United States, including Q-routes and T-routes, and to certain RNAV departure and arrival .