What is "black lead"

Graphite \Graph"ite\, n. [Gr. gra`fein to write: cf. F. graphite. See Graphic.] (Min.) 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.

Graphite battery (Elec.), a voltaic battery consisting of zinc and carbon in sulphuric acid, or other exciting liquid.

n. graphite, one of the allotropes of carbon.

n. used as a lubricant and as a moderator in nuclear reactors [syn: graphite, plumbago]