ephemeral
n.n. lasting for a very short time. You use this to describe things that fade away quickly, like a beautiful sunset or a passing feeling.
n. lasting for a markedly brief duration. Frequently applied to natural phenomena, cultural trends, or states of mind that are inherently transient.
The beauty of a rainbow is ephemeral, fading almost immediately.
Social media trends are highly ephemeral, with users obsessing over a joke one week and completely forgetting it the next.
The sculptor chose to work with ice rather than stone, embracing the ephemeral nature of a medium that would inevitably melt before the exhibition concluded.
From New Latin ephemerus, from Ancient Greek ἐφήμερος (ephḗmeros), the more common form of ἐφημέριος (ephēmérios, “of, for, or during the day, living or lasting but for a day, short-lived, temporary”), from ἐπί (epí, “on”) + ἡμέρα (hēméra, “day”).