1. Chemical:
* Causing burning or corrosion: This is the most common meaning. A caustic substance is one that can damage or destroy living tissue or other materials through chemical reaction. This is often due to the substance's high pH (alkaline) or its ability to react with water to produce heat.
* Examples: Caustic soda (sodium hydroxide), lye, strong acids.
2. Figurative:
* Harsh or biting in speech or manner: This meaning is often used to describe someone's personality or communication style. A caustic remark is one that is intended to be hurtful or sarcastic.
* Example: "The comedian's caustic wit was both funny and offensive."
3. Light:
* Reflecting light in a sharp, concentrated manner: This meaning applies to optics and refers to a surface that reflects light at a specific angle.
* Example: "A caustic curve is formed when light is reflected off a curved surface."
It's important to consider the context when interpreting the word "caustic" to understand its precise meaning.