definition 1: inclined to be irritable and quarrelsome; cranky.
example: The kids were getting very fractious after hours in the car.
definition 2: headstrong and hard to discipline; unruly.
“They talked and gossiped among themselves, strangers soon becoming friends, for the normally fractious and outspoken Londoners had forgotten their differences, at least for a day, united in a common purpose….” (Sharon Kay Penman, When Christ and His Saints Slept)
“Now there are two ways to ride a fractious horse,’ he explained to the Chicago engineers in 1901. “One is to get on him and learn by actual practice how each motion and trick my be best met; the other is to sit on a fence and watch the beast a while, and then retire to the house and at leisure figure out the best way of overcoming his jumps and kicks.” (Tom D. Crouch, The Bishop’s Boys: A Life of Wilbur and Orville Wright)