Top Definition
The act of two lesbians forcefully, but lovingly, inserting the knuckles and or fist in to any orifice of choosing.
Debra whispered softly to Jessica, "Wanna 'Thunder Knuckle'?" as she pumped her fist into the sky.
by GingerJabberwocky May 14, 2011

Free Daily Email

Type your email address below to get our free Urban Word of the Day every morning!

Emails are sent from We'll never spam you.