traction

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

• noun The act of drawing or pulling, especially the drawing of a vehicle or load over a surface by motor power.
• noun The condition of being drawn or pulled.
• noun Pulling power, as of a draft animal or engine.
• noun Adhesive friction, as of a wheel on a track or a tire on a road.
• noun Medicine A sustained pull applied mechanically especially to the arm, leg, or neck so as to correct fractured or dislocated bones, overcome muscle spasms, or relieve pressure.
• noun Informal Impetus or advancement, as toward a desired result.

from The Century Dictionary.

• noun The act of drawing, or the state of being drawn; specifically, in physiology, contraction, as of a muscle.
• noun The act of drawing a body along a surface, as over water or on a railway.
• noun Attraction; attractive power or influence.
• noun The adhesive friction of a body or object, as of a wheel on a rail or a rope on a pulley.
• noun An action the negative of pressure.
• noun In physiology, the axis or direction of the tractive action of a muscle; the line in which a muscle contracts.
• noun In recent use, traffic by means of railroads; railroads, and especially streetrailroads, collectively; the interests and rights represented by such railroads.

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

• noun The act of drawing, or the state of being drawn.
• noun Specifically, the act of drawing a body along a plane by motive power, as the drawing of a carriage by men or horses, the towing of a boat by a tug.
• noun rare Attraction; a drawing toward.
• noun The adhesive friction of a wheel on a rail, a rope on a pulley, or the like.
• noun (Mech.) the angle made with a given plane by the line of direction in which a tractive force acts.
• noun a locomotive for drawing vehicles on highways or in the fields.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun the act of pulling something along a surface using motive power
• noun the condition of being so pulled
• noun Grip
• noun the pulling power of an engine or animal
• noun the adhesive friction of a wheel etc on a surface
• noun medicine a mechanically applied sustained pull, especially to a limb
• noun business the extent of adoption of a new product or service, typically measured in number of customers or level of revenue achieved
• noun politics popular support

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun the friction between a body and the surface on which it moves (as between an automobile tire and the road)
• noun (orthopedics) the act of pulling on a bone or limb (as in a fracture) to relieve pressure or align parts in a special way during healing