Mischievous

Tottenham's Jermain Defoe on why he bit West Ham's Javier Mascherano:

"When the West Ham player fouled me, I reacted in a bit of a mischievous way - my character is a little like that at times." (BBC)

According to Answers.com the word means:

"adj.
Causing mischief.
Playful in a naughty or teasing way.
Troublesome; irritating: a mischievous prank.
Causing harm, injury, or damage: mischievous rumors and falsehoods."

Mascherano is now claiming that Defoe caused harm, while Defoe is steadfast in stating that he was only playing a prank...