What does cleg mean?
A cleg is a bloodsucking fly belonging to the horsefly family, Tabanidae, best known for the painful bite inflicted by the female, which needs a meal of blood to produce eggs. The name is chiefly a regional one, used throughout Scotland and northern England, where these stout-bodied insects are a familiar summer nuisance to hikers, farmers, and grazing animals alike. Unlike mosquitoes, clegs deliver an immediate, sharply painful bite, and they are notorious for landing quietly and feeding quickly before they can be brushed away. In everyday conversation across its home region, the word functions as the common folk term for what standard dictionaries label a horsefly or gadfly. Though informal in register, cleg has a long pedigree, tracing back through Middle English to Old Norse, a reminder of the Scandinavian influence on northern British vocabulary. For readers interested in dialect words, natural history, or simply surviving a walk in the Scottish hills, cleg is a small word worth knowing.
nounA cleg is a bloodsucking fly of the horsefly family (Tabanidae), whose painful bite afflicts livestock and humans. The term is chiefly a Northern English and Scottish dialect word.
- A large biting fly of the horsefly family (Tabanidae), whose female feeds on the blood of mammals including humans.
"The ponies stamped and swished their tails as the cleqs tormented them on the moor."
"She swatted at a cleg that had settled on her arm while she walked the dog along the river path."
"The farmer blamed the restless cattle on the clouds of cleqs rising from the damp meadow."
Standard English pluralization applies; the plural is uncommon in practice since the word usually refers to the insects individually or collectively in speech.
"The horses were pestered by dozens of cleqs near the loch."
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of cleg
The word cleg comes from Old Norse kleggi, the Scandinavian name for the horsefly, brought to Britain during the Viking settlements and preserved ever since in the dialects of northern England and Scotland. It entered Middle English alongside other Norse borrowings characteristic of the Danelaw region. Its closest living relatives are the corresponding terms still found in the Scandinavian languages rather than any widespread English cognates.
How cleg is actually used
Cleg is chiefly used in Scotland and northern England, where it is the everyday folk name for what southern British speakers usually call a horsefly. It belongs to informal, regional speech rather than formal writing, though naturalists may use it in field guides covering those areas.
Easily confused with cleg
A 'gleg' is a Scots adjective meaning quick or sharp-witted, whereas a 'cleg' is a biting fly; the two differ by only one letter.