graphite

noun (n)

1. used as a lubricant and as a moderator in nuclear reactors (noun.substance)

   Sinonim: black lead, plumbago

   Sumber: wordnet30

2. Native carbon in hexagonal crystals, also foliated or granular massive, of black color and metallic luster, and so soft as to leave a trace on paper. It is used for pencils (improperly called lead pencils), for crucibles, and as a lubricator, etc. Often called plumbago or black lead. (noun)

   Sumber: webster1913