ephemeron

from WordNet (r) 3.0 (2006)
ephemeron
    n 1: anything short-lived, as an insect that lives only for a
         day in its winged form [syn: {ephemeron}, {ephemeral}]
    
from The Collaborative International Dictionary of English v.0.48
Ephemeron \E*phem"e*ron\, n.; pl. {Ephemera}. [NL. See
   {Ephemera}.] (Zo["o]l.)
   One of the ephemeral flies.
   [1913 Webster]
    

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