What does "unbridled" mean?

Unbridled: Loosed from the bridle, or as from the bridle; hence, unrestrained; licentious; violent; as, unbridled passions. "Unbridled boldness." B. Jonson. Lands deluged by unbridled floods. Wordsworth. -- Un*bri"dled*ness, n. Abp. Leighton.

Sources