Fugaciousness is a word that describes something fleeting or short-lived. There are several synonyms that can be used instead of fugaciousness such as evanescence, transience, and impermanence. Evanescence is the process of disappearing gradually, transience describes something passing quickly or living in temporary way, while impermanence is the characteristic of being not permanent or lasting. Another synonym is ephemerality, which refers to something lasting for a very short time. Furthermore, there is also volatility which describes something characterized by rapid change or unpredictability. These synonyms can be used interchangeably with the word fugaciousness, depending on the context in which it is used.