Meaning of alderfly

al•der•fly

Pronunciation: (ôl'dur-flī"), [key]
— pl. -flies.
  1. any of several dark-colored neuropterous insects of the family Sialidae, the larvae of which are aquatic and predacious on other aquatic insects.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.
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