*driver*

n. [ From Drive. ] 1. One who, or that which, drives; the person or thing that urges or compels anything else to move onward. [ 1913 Webster ]

2. The person who drives beasts or a carriage; a coachman; a charioteer, etc.; hence, also, one who controls the movements of a any vehicle. [ 1913 Webster +PJC ]

3. An overseer of a gang of slaves or gang of convicts at their work. [ 1913 Webster ]

4. (Mach.) 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:

(a) The driving wheel of a locomotive. (b) An attachment to a lathe, spindle, or face plate to turn a carrier. (c) A crossbar on a grinding mill spindle to drive the upper stone. [ 1913 Webster ]

5. (Naut.) The after sail in a ship or bark, being a fore-and-aft sail attached to a gaff; a spanker. Totten. [ 1913 Webster ]

6. An implement used for driving; as: (a) A mallet. (b) A tamping iron. (c) A cooper's hammer for driving on barrel hoops. (d) A wooden-headed golf club with a long shaft, for playing the longest strokes. [ Webster 1913 Suppl. ]

Driver ant (Zool.), 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. [ 1913 Webster ]