The crossword solution for the term 'Greyhound Alternative' is AMTRAK, which is a six-letter word. AMTRAK is a passenger railroad service that operates throughout the United States and is an alternative to Greyhound bus services. It is owned by the National Railroad Passenger Corporation and is funded by the US government. AMTRAK provides intercity rail services in 46 states and three Canadian provinces, and also offers some international services.