180 \u2013 This is a term that refers to a half rotation. 360 - This is a term that refers to a single full rotation. 540 - This is a term that describes a 540-degree rotation while in the air. This is equal to one and a half full rotations. 720 - This is a term that typically refers to two simultaneous 360-degree turns, either forward or in a backward direction. 900 - This is a term that describes two and a half full rotations. 5-0 Grind - This term describes a type of grind in which the only trick that is grinding is the back truck. 50\/50 - This term describes a type of grind in which both of the trucks are grinding. Abec - This term is used to describe the tolerance rating system that is applied to bearings, designating the level for the bushing\u2019s stress resistance. Higher Abec ratings refer to tighter bearings and lower Abec ratings refer to looser bearings. Acid Drop \u2013 This refers to riding straight off of an obstacle, free falling to the ground. Air \u2013 This is the term that is used to refer to situations where riders are clearing obstacles or jumps. Alley Oop - This refers to a situation where a trick is being performed in an opposite direction from the direction that the skater is moving in. Backside - This refers to a situation where a trick or a turn is being executed in a direction that the rider\u2019s back is facing. Bank - This is any area that is sloped below 90 degrees. Bearings - There are both inner and outer parts in bearings, and the balls ride on them, making it possible for the wheels to turn. Blunt - This describes a situation where a trick is being performed and the board\u2019s contact spot with whatever obstacle is being used is the tail area behind the board\u2019s back trucks. The wheels should also be on top of the item in question. Board \u2013 In skateboarding, this is also known as a deck, and is the platform part that all of the hardware is mounted on to. The most common material used for a skateboard deck is maple laminate. Boardslide or Railslide - This is a trick that involves sliding on an obstacle or a lip where the underside of the board is the contact point. Brain Bucket \u2013 This is a slang term that refers to a helmet. Caballerial - On flat ground this is a term that describes riding fakie, do an ollie 360 without any grabbing. On a vert ramp, this is a term that describes riding fakie, and doing an ollie 360 without grabbing at the lip. This trick was invented by Steve Caballero Carve - This is a term that describes making long curving arcs while skating, especially downhill.