Dictionary 1. (n.) The quality of being fugacious; fugaclousness; volatility; as, fugacity of spirits.2. (a.) Uncertainty; instability. Thesaurus caducity changeableness corruptibility death ephemerality ephemeralness evanescence finitude fleetingness impermanence impermanency instability momentariness mortality mutability perishability transience transiency transientness transitoriness volatility |