What is the opposite of something that is new or original?

The term that serves as the opposite of something new or original is best represented by "trite." This word describes ideas or expressions that are overused and lack freshness or originality; they have become so commonplace that they are no longer impactful or significant. When something is trite, it indicates a lack of novelty or creativity, making it a fitting counterpart to the concept of newness.

In contrast, the other options do not capture this essence of being unoriginal. "Conformity" refers to compliance with established norms or standards but does not specifically denote the idea of something being overused. "Arrogance" denotes an attitude of superiority or self-importance, which is unrelated to originality. "Unprecedented" describes something that has never happened before, which directly contradicts the idea of being trite. Thus, "trite" is the most appropriate choice in this context.