Horse"fly` (?), n.; pl. Horseflies ().
1. Zool.
Any dipterous fly of the family Tabanidae, 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. Zool.
The horse tick or forest fly (Hippobosca).
© Webster 1913.