wilful or (N American) willful /wilˈfŭl/

1. Self-willed, obstinate, headstrong
2. Deliberate, intentional
3. Willing (Shakespeare)

Wilfully

• hard-hitting
• hard house
• hardier
• hardiest
• hardihead
• hardiheads
• hardihood
• hardihoods
• hardily
• hardiment
• hardiments
• hardiness
• hardinesses
• hardish
• hard labour
• hard landing
• hard landings
• hard launch
• hard launches
• hard left
• hard line
• hardline
• hardliner
• hardliners
• hard lines