Passing fancy is a term used to describe something that is temporary or fleeting, an interest that does not last long. There are several synonyms to describe this concept, including "whim," "caprice," "fleeting interest," "faddishness," "craze," and "fad." Other related terms include "episodic interest," "short-lived engagement," and "momentary enthusiasm." These words are useful for describing trends, hobbies, or interests that are popular for a short time but are not likely to endure. Whether discussing fashion, music, or pop culture, these synonyms for passing fancy capture the idea of something that is here today, gone tomorrow.