Madonna
A frontside one footed lien to tail on vert. Doing it backsided is called a Sean Penn who was formerly married to Madonna.
Manual
A balancing trick involving rolling across an obstacle on the back wheels only.
McTwist
A vert trick consisting of a 540° rotation with a backflip. Named after it's inventor, Mike Mcgill.
Melon
A noseboned backside grab (gripping the heelside of the board with your back hand). The closer to the tail the grab is the more stylish the melon grab is. Also called a "Meloncollie"
Method Air
A Method is basically a Melon grab but more "tweaked" behind the skater with their legs bent more.
Miller Flip
A 360° frontside handplant to fakie on vert.
Monsterwalk
A monsterwalk is a chain of 180° pivots that alternate in direction.
Mute
A grab trick similar to an indy grab, but with the front hand, not the rear hand, grabbing the board on its toe side underneath the front knee.