caustick

Noun

caustic (countable and uncountable, plural caustics)

1. Any substance or means which, applied to animal or other organic tissue, burns, corrodes, or destroys it by chemical action; an escharotic.
   • The association of the heavenly bodies with known metals and also with human organs and destinies goes back to ancient Chaldea, the land of astrologers. In Chaucer’s words: ‘The seven bodies eek, lo hear anon. Sol gold is, and Luna silver we declare; Mars yron, Mercurie is quyksilver; Saturnian...2013, John Read, From Alchemy to Chemistry
2. The envelope of reflected or refracted rays of light for a given surface or object.
3. The envelope of reflected or refracted rays for a given curve.
4. (informal, uncountable) Caustic soda.

See all 6 meanings of caustic