This is not well, rash and unbridled boy, To fly the favours of so good a king; To pluck his indignation on thy head By the misprizing of a maid too virtuous For the contempt of empire.
There are no more uses of "unbridled" in the play.
Show samples from other sources
Wolves are also strict monogamists, and although I do not necessarily consider this an admirable trait, it does make the reputation for unbridled promiscuity which we have bestowed on the wolf somewhat hypocritical.
Farley Mowat -- Never Cry Wolf
It was attached to his saddle, which was cinched around his horse, which, when they stopped, could be subtly unbridled, just enough so that with a fierce tug from her end, the chain would rip the saddle off the beast, he’d tumble to the ground, and she would— She sensed Captain Westfall’s attention.