What does the word caustic mean?

Usage examples for caustic

  1. After a good deal of persuasion, for he was at first quite frightened at me, he consented to allow me to apply the caustic. – Travels in the Great Desert of Sahara, in the Years of 1845 and 1846 by James Richardson
  2. Mr. Dodge recovered his temper now that he saw a chance of disconcerting his caustic visitor. – A Mysterious Disappearance by Gordon Holmes