Dromedary
The dromedary is a fast riding-camel. The UPDV preserves the term once — in Isaiah's vision of the wealth of the nations streaming to Zion — and in the other two passages associated with this umbrella renders the underlying Hebrew as "swift steeds" supplying Solomon's stables and the royal post-system of Persia.
The dromedaries of Midian
Isaiah's oracle of Zion's incoming glory pictures the desert routes from the south thick with camels: "The multitude of camels will cover you, the dromedaries of Midian and Ephah; all those from Sheba will come; they will bring gold and frankincense, and will proclaim the good news of the praises of Yahweh" (Isa 60:6).
Swift steeds in royal service
The same family of fast riding-animals shows up in the logistics of two royal courts. Solomon's officers fed the king's mounts on rotation: "Barley also and straw for the horses and swift steeds they brought to the place where [the officers] were, every man according to his charge" (1Ki 4:28). And Ahasuerus' counter-edict in the book of Esther travels by the same kind of fast animal: "And he wrote in the name of King Ahasuerus, and sealed it with the king's ring, and sent letters by posts on horseback, riding on swift steeds that were used in the king's service, bred of the stud" (Esth 8:10).