|1.||guiding, directing, or influencing|
|2.||(prenominal) principal or primary|
|3.||in the first position: the leading car in the procession|
|4.||maths (of a coefficient) associated with the term of highest degree in a polynomial containing one variable: in 5x² + 2x + 3, 5 is the leading coefficient|
lead 1 (lēd)
lead 2 (lěd)
A soft ductile dense metallic element. Atomic number 82; atomic weight 207.19; melting point 327.5°C; boiling point 1,749deg;C; specific gravity 11.35; valence 2, 4.
|lead (lěd) Pronunciation Key
A soft, ductile, heavy, bluish-gray metallic element that is extracted chiefly from galena. It is very durable and resistant to corrosion and is a poor conductor of electricity. Lead is used to make radiation shielding and containers for corrosive substances. It was once commonly used in pipes, solder, roofing, paint, and antiknock compounds in gasoline, but its use in these products has been curtailed because of its toxicity. Atomic number 82; atomic weight 207.2; melting point 327.5°C; boiling point 1,744°C; specific gravity 11.35; valence 2, 4. See Periodic Table. See Note at element.