ephemeral
ih-FEM-er-uladjMeaning lasting a very short time
Memory hook a snowman in the noon sun. Pip’s snowman stood proud at breakfast; by lunch it was a puddle and a carrot. Its life was ephemeral.
The rainbow was ephemeral, gone before Lila could find her camera.
In context Fame online is often ephemeral: a video that millions watch on Monday may be forgotten by Friday.
Similar short-lived, brief, passing, momentary
Opposite lasting, enduring, permanent
From Greek ephemeros, “lasting only a day”: epi (for) + hemera (day).