graphite

noun

1. An allotrope of carbon, consisting of planes of carbon atoms arranged in hexagonal arrays with the planes stacked loosely, that is used as a dry lubricant and in "lead" pencils.
2. Short for graphite-reinforced plastic, a composite plastic made with graphite fibers noted for light weight strength and stiffness.“Modern tennis racquets are made of graphite, fibreglass and other man-made materials.”
3. A grey colour.