Caus"tic (?), Caus"tic*al (?), a. [L. caustucs, Ge. , fr. to burn. Cf. Calm, Ink.]
Capable of destroying the texture of anything or eating away its substance by chemical action; burning; corrosive; searing.
Severe; satirical; sharp; as, a caustic remark.
Caustic curve Optics, a curve to which the ray of light, reflected or refracted by another curve, are tangents, the reflecting or refracting curve and the luminous point being in one plane. -- Caustic lime. See under Lime. -- Caustic potash, Caustic soda Chem., the solid hydroxides potash, KOH, and soda, NaOH, or solutions of the same. -- Caustic silver, nitrate of silver, lunar caustic. -- Caustic surface Optics, a surface to which rays reflected or refracted by another surface are tangents. Caustic curves and surfaces are called catacaustic when formed by reflection, and diacaustic when formed by refraction.
Syn. -- Stinging; cutting; pungent; searching.
© Webster 1913.