—n. 1. a trolley car.
2. a pulley or truck traveling on an overhead track and serving to support and move a suspended object.
3. a grooved metallic wheel or pulley carried on the end of a pole (trol'ley pole") by an electric car or locomotive, and held in contact with an overhead conductor, usually a suspended wire (trol'ley wire"), from which it collects the current for the propulsion of the car or locomotive.
4. 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.
5. a small truck or car operated on a track, as in a mine or factory.
6. a serving cart, as one used to serve desserts.
7. Chiefly Brit.any of various low carts or vehicles, as a railway handcar or costermonger's cart.
8. off one's trolley,Slang. a. in a confused mental state.
b. insane: He's been off his trolley for years, but his family refuses to have him committed.
—v.t., v.i. to convey or go by trolley. Also,trolly.