What does "unprecedented" mean?

The term "unprecedented" refers to something that is not previously known or experienced; it indicates that an event, situation, or occurrence is unusual or without prior example. When something is described as unprecedented, it suggests that it stands out because it has never happened before or is unlike anything that has occurred in the past. This aligns perfectly with the choice indicating that it means "unusual."

In contrast, the other options imply meanings that do not capture the essence of "unprecedented." "Commonplace" suggests regularity or frequent occurrence, which is the opposite of something being unprecedented. "Overdone" implies an excessive nature, which does not pertain to the uniqueness that "unprecedented" conveys. "Exampled" relates to providing examples, which also does not match the meaning of something that is extraordinary or unmatched by prior events.