deer fly

/D IH1 R F L AY0/
noun
  1. 1

    A Eurasian species of louse fly in the family Hippoboscidae, Lipoptena cervi; parasites of elk, deer and other bovine animals, sucking blood and laying eggs in the fur of the host animals.

  2. 2

    A gold or green eyed horsefly of the genus Chrysops in the family Tabanidae; pests to cattle, horses and humans, feeding on their blood.

Source: https://en.wiktionary.org/wiki/deer%20fly