noun, plural shad·flies.
Origin of shadfly
An Americanism dating back to 1830–40; so called because they hatch at the time of year when shad are running
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Examples from the Web for shadfly
Historical Examples of shadfly
We met with ephemer (shadfly) midway, about a mile from the shore, and they evidently fly over the whole lake.The Maine Woods
Henry David Thoreau