from
The Collaborative International Dictionary of English v.0.48
Caustic \Caus"tic\, Caustical \Caus"tic*al\, a. [L. caustucs,
Ge. ?, fr. ? to burn. Cf. {Calm}, {Ink}.]
1. Capable of destroying the texture of anything or eating
away its substance by chemical action; burning; corrosive;
searing.
[1913 Webster]
2. Severe; satirical; sharp; as, a caustic remark.
[1913 Webster]
{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.
[1913 Webster]