Definition of BLACKFLY
: any of various small dark-colored insects
especially : any of a family (Simuliidae and especially genus Simulium) of bloodsucking dipteran flies whose larvae usually live in flowing streams
Examples of blackfly in a Sentence
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
The lakes in northern Indiana were freshly frozen, and big bluegills were schooled up and biting like blackflies under the new ice.
—
Wilson H. Stover, Outdoor Life, 5 Dec. 2024
Bug Shirt Untreated loose-knit fabrics provide no defense from mosquitoes, blackflies, and ticks.
—Andrew Skurka, Outside Online, 21 May 2018
Word History
First Known Use
15th century, in the meaning defined above
Time Traveler
The first known use of blackfly was in the 15th century
Browse Nearby Words
Cite this Entry
“Blackfly.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/blackfly. Accessed 14 Mar. 2025.
Share
Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!