any of several tabanid flies of the genus Chrysops, the female of which is a vector of tularemia in deer, livestock, and humans.
Origin of deer fly
An Americanism dating back to 1850–55
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Examples from the Web for deer fly
Historical Examples of deer fly
As for the deer-fly, and others of his piratical breed, he will bite like a dog at any time.The Forest
Stewart Edward White