A word for a “horseman, rider” in the Quendi and Eldar essay of 1959-60, a reduction of ancient ✶roko-kwēn “✱horse-person” (WJ/372, 407). In notes on the Disaster of Gladden Fields, Tolkien translated roquen as “knight” for a rank higher than a mere ohtar “warrior” (UT/282 note #17), though apparently all ranks rode horses. It may be that the sense “knight” applies only in a [Gondorian?] military context, while in ordinary use roquen can apply to anyone capable of riding a horse. A more general term for a “knight” as a noble person would be arquen.
Quenya
roquen
horseman [but the quenya word does not show gender], rider, knight
roquen
noun. horseman, rider; knight
roquen noun "horseman [but the Quenya word does not show gender], rider, knight" (WJ:372, UT:282)