ROK

ROK/ROKKO is an Elvish root related to horses.

• Quenya: rocco, roquen
• Sindarin: roch, rochben, Rohirrim, Rohan (in Gondor Sindarin)

Unrelated Mannish roots of the same meaning were LUH and KARAB

Other versions of the legendarium

Tolkien experimented with the concept that ROK was a word related to fear and subsequently to Orcs. The origin of the root ROK as 'fear' was the horseman emissary of Melkor who abducted Elves from Cuiviénen. However later Orcs and fear, were related to a different root, ÓROK and RUKU.