fleetingness

/ˈfliːtɪŋnəs/
noun
  1. The quality of lasting only a very short time; brevity.
    • The fleetingness of childhood makes every moment precious.
    • He was struck by the fleetingness of the rainbow as it faded from the sky.
    • Poets often write about the fleetingness of beauty and youth.
Antonyms
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