lead

A metallic element, atomic no. 82, atomic wt. 207.2. SYN: plumbum.

- l. acetate has been used as an astringent in diarrhea, and in aqueous solution as a wet dressing in certain dermatoses. SYN: sugar of l..

- black l. SYN: graphite.

- l. carbonate a heavy white powder that is insoluble in water; occasionally, it is used to relieve irritation in dermatitis, but it is used largely in the manufacture of paint and in the arts and is thus productive of l. poisoning. SYN: ceruse, white l..

- l. chromate SYN: chrome yellow.

- l. monoxide has been used as an ingredient in external applications such as l. plaster. SYN: l. oxide (yellow), litharge, massicot.

- l. oxide (yellow) SYN: l. monoxide.

- red l. SYN: l. tetroxide.

- red oxide of l. SYN: l. tetroxide.

- l. sulfide PbS; the native form in which l. is chiefly found. SYN: galena.

- l. tetraethyl SYN: tetraethyllead.

- l. tetroxide a bright orange-red powder that turns black when heated; used in ointments and plasters. SYN: red l., red oxide of l..

- white l. SYN: l. carbonate.

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lead 'lēd n a flexible or solid insulated conductor connected to or leading out from an electrical device (as an electroencephalograph)

lead 'led n, often attrib

1) a heavy soft malleable ductile plastic but inelastic bluish white metallic element found mostly in combination and used esp. in pipes, cable sheaths, batteries, solder, and shields against radioactivity symbol Pb see ELEMENT (table)

2) WHITE LEAD

3) TETRAETHYL LEAD

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Ⅰ. n.

a portion of an electrocardiographic record that is obtained from a single electrode or a combination of electrodes placed on a particular part of the body (see electrocardiogram, electrocardiography). In the conventional ECG, 12 leads are recorded. Each lead represents the electrical activity of the heart as 'viewed' from a different position on the body surface and may help to localize myocardial damage.

 

Ⅱ. n.

a soft bluish-grey metallic element that forms several poisonous compounds. Acute lead poisoning, which may follow inhalation of lead fumes or dust, causes abdominal pains, vomiting, and diarrhoea, with paralysis and convulsions and sometimes encephalitis. In chronic poisoning a characteristic bluish marking of the gums ('lead line') is seen and the peripheral nerves are affected; there is also anaemia. Treatment is with edetate. The use of lead in paints is now strictly controlled. Symbol: Pb.

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(Pb) (led) a soft, grayish blue metal with poisonous salts; atomic number 82, atomic weight 207.19. Excessive ingestion causes lead poisoning; see under poisoning.