ephemeral

Adjective

• lasting a very short time
  • the ephemeral joys of childhood
    
  • a passing fancy
    
  • youth's transient beauty
    
  • love is transitory but it is eternal
    
  • fugacious blossoms
    

Noun

• anything short-lived, as an insect that lives only for a day in its winged form

Related words

• Synonyms: 
  passing , short-lived , transient , transitory , fugacious , ephemeron