To fart or flatulate on a person's leg.
My boyfriend flap jacked me, and it smelled terrible.
by A. Hermann February 07, 2007
A variation on a pwn created at tl/fwi forum which constitutes the ownage or pwn of a poster who has been gotten to
That wasnt just pwnage, he's been flapjacked!
by =ID= July 08, 2009
The act of putting ones pussy lips on anothers forehead
Man she got so loose that she flapjacked me.
by DamioNIN October 21, 2013