'Cleg' definitions:

Definition of 'cleg'

From: WordNet
noun
Large swift fly the female of which sucks blood of various animals [syn: horsefly, cleg, clegg, horse fly]

Definition of 'Cleg'

From: GCIDE
  • Cleg \Cleg\, n. [Northern Eng. & Scot. gleg: cf. Gael. crethleag.] (Zool.) A small breeze or horsefly. [North of Eng. & Scot.] --Jamieson. [1913 Webster]