reinless
adjEtymology From rein + -less.
1
Not having, or not governed by, reins.
- Lo! with reinless speed A black Tartarian horse of giant frame Comes trampling o’er the dead; the living bleed Beneath the hoofs of that tremendous steed, On which, like to an Angel, robed in white, Sate one waving a sword;—the hosts recede […]1817 December, Percy Bysshe Shelley, “The Revolt of Islam. […]”, in [Mary] Shelley, editor, The Poetical Works of Percy Bysshe Shelley. […], volume I, London: Edward Moxon […], published 1839, →OCLC, page 268:
2
Broadly Not checked or restrained.