Which of the following describes an intentional act that impacts another's reputation negatively?

The term that accurately describes an intentional act that negatively impacts another's reputation is defamation. Defamation involves making false statements about someone that cause harm to their reputation. It can occur in two forms: libel, which refers to written statements, and slander, which pertains to spoken statements. The key aspect of defamation is the intention to damage someone's reputation through misleading information, which fits the context of the question perfectly.

The other options do not convey the same meaning. Critique typically involves a thoughtful analysis or evaluation that may include both positive and negative feedback, but it does not inherently imply an intention to harm someone's reputation. Assessment refers to an evaluation or measurement, usually in a professional or educational context, and does not carry the connotation of damaging someone's reputation. Similarly, a review is often a systematic evaluation or commentary on a product, service, or performance, which may provide feedback but again doesn't inherently involve the intent to harm someone’s standing or character. Thus, defamation is the only term that encapsulates intentional actions that result in damaging someone's reputation.