Driver

Part of speech: noun (n.)

1. One who, or that which, drives; the person or thing that urges or compels anything else to move onward.

2. The person who drives beasts or a carriage; a coachman; a charioteer, etc.; hence, also, one who controls the movements of a locomotive.

3. An overseer of a gang of slaves or gang of convicts at their work.

4. A part that transmits motion to another part by contact with it, or through an intermediate relatively movable part, as a gear which drives another, or a lever which moves another through a link, etc. Specifically:

5. The driving wheel of a locomotive.

6. An attachment to a lathe, spindle, or face plate to turn a carrier.

7. A crossbar on a grinding mill spindle to drive the upper stone.

8. The after sail in a ship or bark, being a fore-and-aft sail attached to a gaff; a spanker. Totten. Driver ant (Zoöl.), a species of African stinging ant; one of the visiting ants (Anomma arcens); -- so called because they move about in vast armies, and drive away or devour all insects and other small animals.