Horse″fly′ (?), n.; pl.Horseflies (�). 1. (Zoöl.) Any dipterous fly of the family Tabanidæ, that stings horses, and sucks their blood.
☞ Of these flies there are numerous species, both in Europe and America. They have a large proboscis with four sharp lancets for piercing the skin. Called also breeze fly. See Illust. under Diptera, and Breeze fly.
2. (Zoöl.) The horse tick or forest fly (Hippobosca).