(Adjective) Noisily or aggressively resisting control, advice, etc.; turbulent, unruly; aggressive, argumentative, bad-tempered.
“Perhaps she realized that however obstreperous her protest at the White House, she would never gain a significant hearing among the federal politicians in Washington, D.C., where she had lived for over a year.”
Fran Grace, Carry A. Nation: Retelling the Life, 2001.