gear

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A toothed machine part, such as a wheel or cylinder, that meshes with another toothed part to transmit motion or to change speed or direction.
• noun A complete assembly that performs a specific function in a larger machine.
• noun A transmission configuration for a specific ratio of engine to axle torque in a motor vehicle.
• noun Equipment, such as tools or clothing, used for a particular activity: synonym: equipment.
• noun Clothing and accessories.
• noun Personal belongings, including clothing.
• noun The harness for a horse.
• noun A ship's rigging.
• noun A sailor's personal effects.
• intransitive verb To equip with gears.
• intransitive verb To connect by gears.
• intransitive verb To put into gear.
• intransitive verb To adjust or adapt so as to make suitable.
• intransitive verb To provide with gear; equip.
• intransitive verb To come into or be in gear.
• intransitive verb To shift a transmission.
• intransitive verb To become adjusted so as to fit or blend.

from The Century Dictionary.

• To put into gear; prepare for operation; fit with gear or gearing: as, to gear up a wagon; to gear a machine or an engine.
• In machinery, to fit into another part, as one part of gearing into another. See gearing.
• noun The diameter of an imaginary wheel whose circumference is equal to the distance traversed by a safety-bicycle during a single revolution of the pedals: as, a 72-inch gear.
• noun A toothed wheel in which the axial lines of any one tooth are made up of two helical lines of equal pitch, one right-handed and one left-handed, which meet at the center of the face or breadth of the toothed surface. Such gears are called herring-bone gears, from the V-shape which each tooth receives. In this latter form they can only be used when the shafts are parallel.
• noun A state of preparation or fitness; a suitable or fitting condition: as, to be out of gear; to bring anything into gear.
• noun Whatever is prepared for use or wear; manufactured stuff or material; hence, habit; dress; ornaments; armor.
• noun Any special set of things forming essential parts or appurtenances, or utilized for or connected with some special act, occupation, etc.: as, hunting-gear.
• noun Naut.. the ropes, blocks, etc., belonging to any particular sail or spar: as, the mainsail-gear, the foretop-mast-gear.
• noun In machinery, the appliances or furnishings connected with the acting parts of any piece of mechanism: as, expansion-gear, valve-gear. More particularly— Toothed wheels collectively. The connection of toothed wheels with each other; gearing: as, to throw machinery into or out of gear.
• noun A coal-miners' set of tools.
• noun plural In coal-mining, staging and rails for shipping coal on wharves.
• noun Goods; property in general.
• noun A matter; an affair; affairs collectively.
• noun Ordinary manner; behavior; custom; practice.

from the GNU version of the Collaborative International Dictionary of English.

• intransitive verb (Mach.) To be in, or come into, gear.
• transitive verb To dress; to put gear on; to harness.
• transitive verb (Mach.) To provide with gearing.
• transitive verb To adapt toward some specific purpose.
• transitive verb driven through twofold compound gearing, to increase the force or speed; -- said of a machine.
• noun Clothing; garments; ornaments.
• noun Goods; property; household stuff.
• noun Whatever is prepared for use or wear; manufactured stuff or material.
• noun The harness of horses or cattle; trapping.
• noun Scot. Warlike accouterments.
• noun obsolete Manner; custom; behavior.
• noun obsolete Business matters; affairs; concern.
• noun A toothed wheel, or cogwheel; ; also, toothed wheels, collectively.