Definition of unreined in US English:

unreined

adjective

  • Free from restraint or control; unrestrained, unleashed. Also in literal sense: (of a horse, etc.) free from the control of the reins.

Origin

Late 15th century; earliest use found in Chartier's Traité de l'Esperance. From un- + reined.

Pronunciation

unreined

/(ˌ)ʌnˈreɪnd/