any of several tabanid flies of the genus Chrysops, the female of which is a vector of tularemia in deer, livestock, and humans.
Words Of The 90s: Fly Slang That Should Be Used TodayRead more in this article about some frequently asked questions and fun facts related to our definitions.
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
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