Definition of caustic

The word "caustic" has a fascinating history. It originates from the Greek word "kaustikos," meaning "burning" or "scorching." In ancient Greece, caustic substances were those that could cause burning or blistering on the skin. The term was later adopted in medieval Latin as "causticus," referring to a strong acid or alkali that could burn or corrode. In the 15th century, the word "caustic" was borrowed into English to describe a substance that could cause chemical burns or lesions. Over time, the term expanded to include figurative uses, describing sharp, biting, or sarcastic language or criticism that could "burn" or wound others' feelings. Today, the word "caustic" is commonly used in many fields, including chemistry, medicine, and literature, to describe a range of meanings related to burning, corrosion, or scorching.