Ollie

A no handed air performed by tapping the tail of the board on the ground or ramp surface. Named after Alan Gelfend.

Pads

Usually knee and elbow pads, which skateboarders use to protect themselves when riding. 
Usually only used for ramp riding, but often required in situations which require insurance.

Pivot

A trick or part of a trick where the truck touches the top of the lip or coping for just a moment before reentry.

Poser

Someone who acts better than they are.

Quarterpipe

A halfpipe with one wall; a banked hit.

Rad

An overused term which can mean many things, but is originally derived from the word radical, which simply put, means the extreme. In early interviews with the first pro skaters, radical was a big word, and it has come to mean just about anything (usually) good. 
 
Synonymous with cool.

Ramp boards

Large deck and firm wheels mounted on wide trucks to make the board as stable as possible.

Regular foot

To ride with the left foot forward.

Retainer

Keep the ball bearings spaced correctly.

Revert

An extra element to add to a trick by continuing the motion of the trick until the board and skater are going backwards. 
 
To clarify: to do a frontside air revert is to do a frontside air , land, and then to turn around, in the frontside direction, and go backwards towards the next wall. 
 
The motion here completes a circle, all in the same direction. 
Therefore, a backside ollie revert means to spin in the backside direction. (clockwise for regular footers)

Riser

Plastic piece under the base of the truck to raise it for better wheel clearance. Often used with larger wheels.

Rock and roll

A lip trick where the underside of the board and wheels are tapped on the lip before a kickturn to reenter.

Rock to fakie

A trick where the underside of the board and wheels are tapped on the lip before the rider reenters traveling backwards.

rotational inertia

a measure of a resistance to being turned, depending on both the mass of the object and how that mass is distributed.

Sealed bearing

A bearing system that uses a physical seal to keep out water and debris.

Session

A period of skating.

Sex Change

A kickflip with a body-varial.

Shuffle

An extra element to add to a trick by landing sideways, or with the wheels parallel to the lip, and then sliding the wheels to reenter backwards. 
 
To clarify: to do a backside air shuffle, do the motion for a backside air, but as you reenter, land sideways with the wheels just below coping and slide to a the fakie position. Can also be done on a curb, bank, etc.

Sick

Big, crazy, cool, incredibly difficult.

Skate Camp

A summer camp for skateboarders where street obstacles, ramps, bowls, and banks can be skated without hassle from cops, parents, etc.

Skate park

A place, either public or privately owned, that is designed for skateboarding. Can be cement, asphalt, or with ramps.

Skate Rock

A term coined in the early eighties and made famous by Thrasher magazine. Represented the bands whose members rode skateboards. Could be any type of music, but is noted for its generally up-tempo beats.

Skateboarder Magazine

The first skateboard magazine, which published four issues in 1966 and 1967, and then reemerged just after the urethane wheel in 1975. Endured until 1980, when, with the close of many skate parks, it became Action Now, a multi-sport magazine. Action Now eventually folded in 1981.

Skid Lid

A helmet.

Slam

A fall, usually accompanied by minor or major injury, which is unexpected. 
 
i.e. the skater makes the commitment to the trick and doesn't realize his mistake until he slams.

Smith grind

A type of grind trick where the back truck is grinding, while the rail of the board is also grinding the lip of the ramp or obstacle. 
 
Frontside Smith Grind: the toe-side edge is involved;  
Backside Smith Grind: the heel-side edge is involved.

Spine ramp

Two half pipes placed back to back creating a double U shape.

Spring planting

A face plant.

Stain

Normal deck without a slick bottom.

Stalefish air

The frontside trick where the rear hand grabs the heel edge behind the rear between the bindings while the front leg is boned.

Stalled

When a maneuver is intentionally started late into a jump/trick.

Stoked

adj. Describes riders when they are pumped up and confident.

Street boards

Shorter and narrower than ramp boards. Usually has a shorter wheelbase than a ramp board.

street skating

skating on streets, curbs, benches, handrails and other elements of urban and suburban landscapes.

Swing weight

The distribution of weight from the tip and tail to the center of the board. To balance a board and control its ability to initiate rotation or to stop rotation in relationship to its overall weight.

Switch

Any trick where the take off or landing is backwards.

Switch stance

When the feet are placed in the opposite of the normal stance and you are going forward with a slightly different balance point than in your normal stance. Not the same as fakie where you ride backwards with your normal balance and stance.

Switchback

Used to describe turns that are around 180 degrees.

Varial

An aerial where the board is spun from backwards to forwards beneath the feet.

Vert ramp

a half-pipe, usually at least 8 feet tall, with steep sides that are perfectly vertical near the top.

Vert Skating

skating on ramps and other vertical structures specifically designed for skating.

Wall

Any bank that is at or above 90 degrees.

Wallride

To ride on a wall that has no transition.

Wheel Base

The distance between the front and back wheels of any vehicle with two axles. 
In skateboarding this is measured between the two sets of inner-most truck holes. 
(the rear set of the front truck and the front set of the back truck).

Wheel Scrubbing

To remove "gunk" and residue from a new wheel to ensure proper adhesion.

Wheels

Attached to the truck - rolling devices which are usually made of urethane. In addition to the standard wheels, there are now those which have a nylon or high-tech plastic on the interior part of the wheel.

Wipeout

A crash.

Wood core

Various type of wood used to provide the shape and thickness of a board.

work

force applied over a distance—for example, you do work when you push a box across the floor, but not when you push on a locked door;  
work done on an object or system results in an increase in the energy of that system.

Zonk

Hit the wall.