Adjective

1. Capable of burning, corroding or destroying organic tissue
2. sharp, bitter, cutting, biting, sarcastic

Synonyms

• (capable of destroying tissue): acidic, biting, burning, corrosive, searing
• (severe, sharp): bitchy, biting, catty, mordacious, nasty, sharp, spiteful

Quotations

• 1843: "How now!" said Scrooge, caustic and cold as ever. — Charles Dickens, A Christmas Carol
• 1843: The bargain was not concluded as easily as might have been expected though, for Scadder was caustic and ill-humoured, and cast much unnecessary opposition in the way — Charles Dickens, Martin Chuzzlewit
• 1853: Madame Beck esteemed me learned and blue; Miss Fanshawe, caustic, ironic, and cynical — Charlotte Bronte, Villette
• 1857:The Secretary and the Assistant-Secretaries would say little caustic things about him to the senior clerks, and seemed somewhat to begrudge him his new honours. — Anthony Trollope, The Three Clerks
• 1886: this set of worthies, who were only too prone to shut up their emotions with caustic words. — Thomas Hardy, The Mayor of Casterbridge
• 1930s???: though he came too late / To join the martyrs, there was still a place / Among the tempters for a caustic tongue / / To test the resolution of the young / With tales of the small failings of the great — W.H.Auden, 'The Quest'

Noun

1. Any substance or means which, applied to animal or other organic tissue, burns, corrodes, or destroys it by chemical action; an escharotic.
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. caustic soda