n.; pl.Horseflies1. (Zool.) Any dipterous fly of the family Tabanidae, that stings horses, and sucks their blood. [ 1913 Webster ]
☞ 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. [ 1913 Webster ]
2. (Zool.) The horse tick or forest fly (Hippobosca). [ 1913 Webster ]