Mahalo
Hawaiian word meaning thank you, and other forms of gratitude, admiration, praise, etc.

Make Wave
truck. To go for a wave and make it as opposed to getting tossed off your board and pounded by the wave.

Mal
Something that's lame, dumb, or overall sucky.

Malibu
The name of a longboard in most places except United States. Originated in California.

Man in Grey Suit
What surfers call a shark. As in; you known those big Great White ones? In California they're called "The Landlord."

Manning Slabs
To exhibit extreme cool under pressure or in a heavy situation. Related to surfing it means to surf well under very sketchy, critical or other condition where most surfers would fail.

McFlip
A move that was developed by a locally famous surfer in Indialantic, Florida at a spot called Two Roads (Uluwaturoads, Imperial Suites) that was developed when nobody else was watching. A maneuver that entails a full flip and a 360 degree turn mid-air turn that has yet to be seen by many other except for locals. No residing in San Diego, California, this maneuver has never been perfected by anyone else.

Mean Wave Direction
The measurement in degrees from true North corresponding to the energy level of the dominant wave period.

MEKP
Methyl ethyl ketone peroxide, a noxious toxic chemical used in small quantities as a catalyst or "hardener" for polyester resin.

Mercator
A type of chart that shows a flat surface to the Earth, which is actually a curved surface. A straight line on the curved surface of the Earth actually shows up as a curved Great Circle line on a Mercator chart.

Meter
The metric equivalent of 3.28 feet.

Meters per second
A scientific measurement for speed, which equals about one half of a knot. Example: 10 meters per second would equal about 5 knots.

Micro-mini
A perfectly shaped wave that's generally found breaking close to shore. Too small to surf, but still contain the classic elements of a good wave.

Midpoint
The point on a surfboard exactly halfway between the nose and tail; not necessarily the wide point (see wide point).

Millibars (mb)
Units of atmospheric pressure equal to one thousandth of a bar. Standard atmospheric pressure at sea level is about 1,013 millibars. Strong high-pressure systems can be around 1040 millibars while deep low-pressure systems can drop to around 930 millibars.

Millimeters (mm)
Refers to thickness of neoprene. Wetsuits are rarely all one thickness, usually using a thicker rubber in the torso for warmth and a thinner rubber in the arms and legs for flexibility. While thickness can range from 0.5mm to 5mm, typical suits are 3/2mm for cool to cold water and 4/3 for cold water.

Mini-back zip
Small zipper, often flanked by a layer of rubber behind it to prevent seepage, which was developed as a compromise between ease of entry of zippered suits and flexibility and warmth of zipperless suits.

Mini-Malibu
The name of mid-sized board with characteristics similar to a longboard. They remain popular to this day because of their versatility in many types of waves and conditions.

Minigun
A design credited to Dick Brewer of Hawaii around 1968, which among other things featured the first hints of the modern outline in a pulled-in tail and pin-nose.

Molding/Molded Boards
Generic term for a type of surfboard manufacturing in which a hard plastic molded shell is injected with expanding foam; currently practiced by Europe-based BiC Surfboards.

Mole in the Hole 
Tubed, Green Room, shacked, etc.

Mondo
Sweet, killer, cool, epic.

Monochromatic waves
Waves generated in a laboratory wave pool for scientific study where each wave has the same length and period.

Muku
The side of a wave near the crest or breaking section of a wave (see Lala).

Multi-suck
Similar to a double-up, but much more intense. Occurs when a double-up approaches a strong outflow or rebounding of water from waves that have already broken and are receding.

Munched
To be taken over the falls on a close out wave. Used to describe a wipe out were the lip of a wave on a closeout comes down hard on the surfer.

Murph
Person that gets no respect in the line up because he is a renowned kook and should not be in the water.

Munchburger
A slow, mushy wave lacking power. Surfable with a longboard or funboard. Suitable for beginners.

Mushy
A surf condition in which waves are crumbly and soft without any steepness or much energy. Gutless and weak.

Mysto Break 
Any elusive break that only fires on rare occasions under specific conditions. Also referred to as a 'secret surf spot.' A mysto break is not considered an actual surf spot.