Fads are brief periods of intense interest or popularity in certain trends, products, or activities. In addition to fads, there are several synonyms used to describe these phenomena. One of the most popular is "craze," which also denotes an obsession or infatuation with a particular item or activity. Another synonym is "fadism," which tends to make a distinction between the craze itself and the act of following it. Other phrases that might be used to describe a fad include "flash in the pan," "short-lived trend," and "fad diet." Essentially, all of these terms refer to something that is currently popular or trendy, but may not last in the long run.