horn fly

noun

: a small dark gray European dipteran fly (Haematobia irritans) that has been introduced into North America where it is a blood-sucking pest especially of cattle

Word History

First Known Use

1708, in the meaning defined above

Time Traveler
The first known use of horn fly was in 1708

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Cite this Entry

“Horn fly.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/horn%20fly. Accessed 2 Jul. 2026.

Medical Definition

horn fly

noun
: a small black European dipteran fly (Haematobia irritans of the family Muscidae) that has been introduced into North America where it is a bloodsucking pest of cattle

called also cattle fly

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