Caustic

caustic, any strongly corrosive chemical substance, especially one that attacks organic matter. A caustic alkali is a metal hydroxide, especially that of an alkali metal; caustic soda is sodium hydroxide, and caustic potash is potassium hydroxide. Silver nitrate is another caustic substance; it is sometimes called lunar caustic. Most inorganic acids, e.g., sulfuric acid, are caustic, especially when concentrated.

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caustic

1. capable of burning or corroding by chemical action

2. of, relating to, or denoting light that is reflected or refracted by a curved surface

3. a surface that envelopes the light rays reflected or refracted by a curved surface

4. a curve formed by the intersection of a caustic surface with a plane

5. Chem a caustic substance, esp an alkali

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caustic [′kȯ·stik]

(chemistry)

Burning or corrosive.

A hydroxide of a light metal.

(optics)

A curve or surface which is tangent to the rays of an initially parallel beam after reflection or refraction in an optical system.

(physics)

A curve or surface which is tangent to adjacent orthogonals to waves that have been reflected or refracted from a curved surface.

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Caustic 

a medicinal substance that exerts a local cauterizing effect when applied to the skin or a mucous membrane. Caustics are used for the destruction of certain skin neoplasms and for disinfection. They also perform antimicrobial activity by destroying the proteins of microorganisms. Caustics include such acids as fuming nitric acid and trichloracetic acid, such salts of heavy metals as silver nitrate and zinc sulfate, and alcohol solutions of iodine. Caustics are used in small concentrations as astringents.