wilful

Etymology

From Middle English wilful; equivalent to will + -ful.

adj

1. Intentional; deliberate.
   Knowingly or unknowingly, every therapist assumes that each client possesses the capacity to change through willful choice. 2005, Irvin D. Yalom, Molyn Leszcz, The Theory and Practice of Group Psychotherapy, page 182
2. Stubborn and determined.
   Troponyms: spiteful, malicious
   Mary had taken the whim into her willful head, and Jane could not dissuade her. 1893, Edwin Caskoden, When Knighthood Was in Flower, page 110
   "He's as willful as you," Rizpah said. "If you let him hurt himself again, so help me, I'll — " 1995, Francine Rivers, As Sure as the Dawn, page 232
   You had a pampered upbringing, and possessed enough of a willful streak that I wanted to slap you at times 2007, Roger K. Thomas, Kinshu: Autumn Brocade, translation of original by Teru Miyamoto, page 136