asbestos

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. Either of two incombustible, chemical-resistant, fibrous mineral forms of impure magnesium silicate, used for fireproofing, electrical insulation, building materials, brake linings, and chemical filters.
2. adj. Of, made of, or containing one or the other of these two mineral forms.

Century Dictionary and Cyclopedia

1. n. A fabulous stone, which, once set on fire, could not be quenched: a notion due to observation of the effect of cold water in heating quicklime.
2. n. A supposed kind of flax, alleged to be incombustible.
3. n. A fibrous variety of amphibole or hornblende, composed of separable filaments, with a silky luster; also, in popular use, a similar variety of serpentine called chrysotile. Its fibers are sometimes delicate, flexible, and elastic, sometimes stiff and brittle, and when reduced to a powder are soft to the touch. Its colors are various shades of white, gray, or green, passing into brown, red, or black. It is incombustible, and is therefore used for making lamp-wicks, paper, firemen's clothing, building materials, twine, and rope for packing steam-joints and pistons; it is also prepared as a cement for protecting heated surfaces, roofs, and floors, and for various fire-proofing purposes. It is mined in Canada, Vermont, Virginia, South Carolina, and in Staten Island, New York. Some varieties are compact, and take a fine polish; others are loose, like flax or silky wool. Ligniform asbestos, or mountain-wood, is a variety presenting an irregular filamentous structure, like wood. Other varieties of hornblende asbestos are rock-cork, mountain-leather, fossil paper, and fossil flax. A fine variety is called amiantus (which see).

Wiktionary

1. n. Any of several fibrous mineral forms of magnesium silicate, used for fireproofing, electrical insulation, building materials, brake linings, and chemical filters; the small fibres can cause cancer when lodged in the lungs.
2. adj. Of, or relating to asbestos.

WordNet 3.0

1. n. a fibrous amphibole; used for making fireproof articles; inhaling fibers can cause asbestosis or lung cancer