Englishunbridled
adjective
she strikes the ball with an unbridled enthusiasm:
unrestrained, unconstrained, uncontrolled, uninhibited, unrestricted, unchecked, uncurbed, rampant, runaway, irrepressible, unstoppable, uncontainable, unquenchable;
excessive, wild, intemperate, immoderate, wanton, self-indulgent.
▷antonyms restrained, controlled.
unbridled Oxford Dictionary of English