Refers to an electric streetcar or tram, typically running on rails in a city. Also used for a shopping cart or luggage cart in some contexts, but the core sense is a rail vehicle.
It's convenient to get around the city by trolley.
観光客はトロリーに乗って名所を回った。
The tourists rode the trolley to visit the sights.
Borrowed from English 'trolley', referring to an electric streetcar or tram.