look up any word, like fellated:
 
1.
A joining of the four non-thumb fingers, like a horizontal high five, with fingers straight and interlocked, met and squeezed. Most common use: congratulations. Can also be romantic or supportive, a gesture between friends, signifying solidarity.
"Good joke, dude, fingerlock!"

"I'm glad you came, babe, fingerlock me."

"Sweetheart, you'll be okay, fingerlock and forget!"
by Tubetop2012 July 09, 2012