What word best describes a deceptive appearance or illusion?

The word "illusory" is the best choice because it directly relates to the concept of something that is deceptive in appearance or an illusion. It describes a situation where what is perceived is not an accurate representation of reality, giving a sense of false perception or misleading appearance. This term often applies in contexts where one might be misled by appearances, such as in art, dreams, or magical performances where things are not as they seem.

In contrast, the other options do not align with the meaning of a deceptive appearance. "Nonplused" refers to a state of being perplexed or puzzled, rather than an illusion. "Poverty" denotes a state of being impoverished, which does not convey any sense of deception or illusion. Lastly, "miserly" describes an unwillingness to part with resources, particularly money, and does not relate to appearance or illusionary qualities. Thus, "illusory" stands out as the term that captures the essence of a deceptive appearance or illusion.