graphite

n [U] soft black substance (a form of carbon) used in making lead pencils, in lubrication, and for slowing down neutrons in atomic reactors 石墨.

granny, granny (also grannie), granny flat, granny knot, grant, granted, granular, granulate, granulated sugar, granule, grape, grape-shot, grape-sugar, grape-vine, grapefruit, graph, graph paper, graphic, graphically, graphics, graphologist, graphology, grapnel, grapple, grappling-iron, grasp, grasp at, grasping, graspingly, grass, grass roots, grass snake, grass widow, grass-seed, grasshopper, grassland, grassy, grate, grateful, gratefully,