capable of destroying or eating away by chemical action; corrosive
bitterly sarcastic or cutting
The Badger's caustic, not to say brutal, remarks, may be imagined — Kenneth Grahame
in physics, of or being a curve formed by rays coming from a point and reflected or refracted by a curved surface
of or being a surface with the shape of such a curve
caustically adv
causticity /koʹstisiti, kaw-/ noun
[via Latinfrom Greek kaustikos, from kaiein to burn]