The material (usually black or dark gray) which allows a pencil to work. Usually a mixture of graphite and smaller amounts of other material, but not actual lead.

(chemistry) A toxic organometallic compound, (C₂H₅)₄Pb, added to petroleum/gasoline as an antiknock agent.

(pathology) A chronic intoxication produced by the absorption of lead into the body, characterized by severe colicky pains, a dark line along the gums, and local muscular paralysis.

(linear algebra) A main diagonal.

unrefined lead, cast in blocks called pigs

Used other than figuratively or idiomatically: see lead, out. / (poker slang) To bet into a pot postflop from the first betting position.

(printing, historical, transitive) To pad out (text) by inserting lead slugs between words.

(inorganic chemistry) A yellow oxide of lead, PbO, used in the manufacture of paints and glass.

A bright red, poisonous oxide of lead, Pb₃O₄, used as a pigment and in glass and ceramics. / (military slang, dated) Tomato ketchup.

On a steam locomotive, an unpowered wheel located in front of the driving wheels.