a trolley car.

a pulley or truck traveling on an overhead track and serving to support and move a suspended object.

a grooved metallic wheel or pulley carried on the end of a pole (trolley pole) by an electric car or locomotive, and held in contact with an overhead conductor, usually a suspended wire (trolley wire), from which it collects the current for the propulsion of the car or locomotive.

any of various devices for collecting current for such a purpose, as a pantograph, or a bowlike structure (bow trolley) sliding along an overhead wire, or a device (underground trolley) for taking current from the underground wire or conductor used by some electric railways.

a small truck or car operated on a track, as in a mine or factory.

a serving cart, as one used to serve desserts.

Chiefly British . any of various low carts or vehicles, as a railway handcar or costermonger's cart.

to convey or go by trolley. ?

off one's trolley

Slang .

in a confused mental state.

insane

He's been off his trolley for years, but his family refuses to have him committed.