1911 Encyclopædia Britannica/Gear

GEAR (connected with “garb,” properly elegance, fashion, especially of dress, and with “gar,” to cause to do, only found in Scottish and northern dialects; the root of the word is seen in the Old Teut. garwjan, to make ready), an outfit, applied to the wearing apparel of a person, or to the harness and trappings of a horse or any draft animal, as riding-gear, hunting-gear, &c.; also to household goods or stuff. The phrase “out of gear,” though now connected with the mechanical application of the word, was originally used to signify “out of harness” or condition, not ready to work, not fit. The word is also used of apparatus generally, and especially of the parts collectively in a machine by which motion is transmitted from one part to another by a series of cog-wheels, continuous bands, &c. It is used in a special sense in reference to a bicycle, meaning the diameter of an imaginary wheel, the circumference of which is equal to the distance accomplished by one revolution of the pedals (see Bicycle).