Word of the Day -- Fugacious

I suppose a phantasm could be considered this, at least sometimes?
Fugacious means lasting a short time : evanescent.  It is often used to describe immaterial things like emotions, but not always. Botanists, for example, use it to describe plant parts that wither or fall off before the usual time. Things that are fugacious are fleeting, and etymologically they can also be said to be fleeing. "Fugacious" derives from the Latin verb "fugere," which means "to flee." Other descendants of "fugere" include "fugitive," "refuge," and "subterfuge."