auto, automobile, car, motorcar, machine - 4-wheeled motor vehicle; usually propelled by an internal combustion engine; "he needs a car to get to work"

rubbing, friction - the resistance encountered when one body is moved in contact with another

pull, pulling - the act of pulling; applying force to move something toward or with you; "the pull up the hill had him breathing harder"; "his strenuous pulling strained his back"

orthopaedics, orthopedics - the branch of medical science concerned with disorders or deformities of the spine and joints