Trolley bus, also known as trackless trolley, is a type of electric bus that runs on overhead wires like a tram or streetcar. But there are some other words that can be used as synonyms for this word. One such synonym is "electric bus," which is a catch-all term for any bus that is powered by electricity. "Electric trolley bus" is another term that emphasizes the use of overhead wires to power the vehicle. "E-bus" is a simple and modern synonym that is common in everyday language. Lastly, "transit bus" is a broader term that includes all types of buses used for public transportation.