Source: Melvin M. Slapperson's definitions

M-slap

The act of pwning somebody to such an extremity that only slapping them with your genitalia could possibly match the awesomeness of that pwnage.
Not to be confused with the interest group MSLAP (Mankind Supporting Lethal Attacks on Polar-life)

Billy M-Slapped Jane when he made a humorous comment about her bulimic sister.

by Source: Melvin M. Slapperson January 1, 2009