Which word describes a tone that is harsh or corrosive?

The term "acerbic" is used to describe a tone or manner that is sharp, biting, or harsh, often with a critical or sarcastic edge. It conveys a sense of acidity, similar to how acids can corrode materials, hence its connection to something that can be corrosive in nature. When applied to language or communication, an acerbic tone can hurt or cut in a way that is both pointed and intense, often leaving a significant impact on the listener or reader.

In contrast, adulation refers to excessive praise or flattery, which does not align with the idea of harshness. Acumen relates to the ability to make good judgments or quick decisions, focusing on intellect rather than tone. Finally, diffident describes someone who is shy or lacking in confidence, which is not related to the idea of a harsh or corrosive tone. Thus, acerbic is the only option that accurately captures the essence of a tone that is both harsh and potentially corrosive.