1. the quality of being caustic; the ability to burn, corrode, or destroy organic tissue
Usage: chemistry/science context
2. harshness or severity of tone, manner, or speech; biting wit or sarcasm
Usage: figurative use

Examples

• The causticity of the chemical solution required careful handling and protective equipment.
• Her causticity in conversation often offended those who didn't appreciate her sharp humor.
• The causticity of sodium hydroxide makes it dangerous for untrained users.
• His remarks were known for their causticity, cutting through pretense with brutal honesty.
• The causticity of the critic's review left the author feeling wounded.
• Industrial processes must account for the causticity of certain compounds when selecting materials.