Obstreperous: loud, noisy, clamorous, defiant, disobedient, unruly
Obstreperous comes from the Latin word Obstrepere, which means “to make a loud noise” or “to roar against”, and itself comes from two other Latin words, ob meaning “against” or “right before”, and strepere meaning “to make a noise”. So, Obstrepere literally means “to make a noise against”, or in other words, “to be defiant”.
“The obstreperous children constantly got themselves into trouble.”
“Tim did not like how obstreperous his new dog was.”