If you're new to mountain biking chances are you've probably heard some terms on videos, websites, or on the trail that you didn't understand but don't worry my guide below will help you master all the terms you need to know.  This is by no means a complete list so feel free to leave a comment for any I may have missed.  

    A

• Apex:  Is the geometric center of a turn which gives you the straightest line through the turn while allowing you the highest speed.

• Armor: 1 The protective gear you wear such as a chest protector, elbow and knee pads, helmet, etc.  2 Parts of the trail covered by rocks, bricks, or another hard object to prevent the trail from deteriorating in that spot. 

• Attack Position:  Body position used when going downhill, over technical sections, or over unknown trail. Also known as the ready position where you are standing above the saddle with your knees and elbows bent, chest close to the handle bars and eyes looking forward.

B

• B-line:  An easier alternate route around and obstacle or feature.

• Baby Heads:  Small rocks in the trail roughly the size of... well a babies head.

• Bail:  When you are crashing or about to crash and you jump off your bike to avoid a more serious crash and injuries.

• Bark Tattoo:  A cut or scrap you received from bushing against a tree you are passing by.  

• Berm:  A banked corner formed of dirt, rocks, or other materials to assist in carrying speed around a corner.  

• Biff:  When you crash.

• Boardwalk:  A man made feature built over an unrideable area such as a marshy area.

• Bomb:  Going as fast as you can.  

• Bonk:  When you run out of energy.

• Breakaway:  A style of helmet that has a removeable chin guard so it can be used as a full face helmet or a half lid.

• Brown Pow:  The dirt all mountain bikers want to ride on.  It is a grippy type of loam.

• BSO:  Bike shaped object, a term used to refer to box store bikes. 

• Bunny Hop: An essential beginner's skill you use to hop the front and back tire over an obstacle.  

C

• Case:  When you don't quite clear a jump and your back tire hits the top of the landing area.  The end result can range anywhere from it being no big deal all the way to going over the handle bars

• Chain Suck:  When the chain either falls off or gets jammed.

• Chain Tattoo:  The grease stain left on your leg or pants leg after touching the chain.

• Chatter: Loose rocky section of the trail.

• Chunder:  Similar to chatter but with larger debris or a higher volume.

• Chunky:  A section of trail with lots of rock but unlike chatter and chunder these rocks are embedded into the trail.

• Chute:  A steep and narrow section of a trail.

• Clean:  To ride an entire trail without crashing or dabbing.   See dab

• Cover:  Covering your brakes by keeping at least a finger on them at all times.

• Cross country (XC):  A style of riding covering multiple types including uphill, downhill, and technical sections.  

• Cyclocross:  A style of riding that is a cross between road biking, steeplechase, and mountain biking in which the rider is often required to get off the bike and carry it up stairs or steep inclines.  

• Cyclopath:  A person who enjoys the pain of mountain biking.  

D

• Dab:  When you take your foot off the pedal to either catch yourself from falling or while turning.  

• Dialed:  When your bike is set up perfectly. 

• Dead Sailor:  When you lock your body up after taking off from a jump which often results in eating dirt.  See Eat Dirt

• Double Track:  A trail that is often as wide as a road.

• Downhill (DH):  A style of riding which is simply all downhill with obstacles and technical features.  

• Downslope:  The landing area which is angled down to prevent you from landing flat.

• Drop:  A natural or manmade feature that suddenly drops off and is too high and steep to roll over.

• Dropping In:  When you begin your decent.

• Dual Suspension (Full Squish):  A bike that has both front and rear suspension.

E

• Endo:  A crash in which you go over the handlebars.  See also OTB

• Enduro:   A style of riding that is a mix of downhill and cross country.     

F

• Feathering:   A braking technique that involves using just enough brake to slow down but not completely stop which would cause the tires to lose traction and cause a lose of control over the bike.

• Feature:   Any obstacle in the trail typically a jump, rock garden, roller etc.

• Flow:  Whether a flow trail or just a trail built in such a way that the jumps, features, and berms flow together requiring little to no pedaling to keep going down the trail.

• Full Face:   A helmet that has a chin guard that offers face protection.

G

• Gap Jump:  A jump with a space between the take off and the landing that you must clear unlike a tabletop jump.  See also Tabletop 

• Gnar:  A trail or section that is extra dangerous, difficult, or technical.  

• Greasy:  When a trail is wet and there isn't a lot of traction.  Or when you splash chain oil on your brakes causing reduced stopping power.

• Grunter:  A difficult climb that will probably cause some grunting.

H

• Half Lid:  A helmet without a chin guard offering no face protection.  

• Hardtail:  A bike with only front suspension.

• Hero Dirt:  Wet tacky dirt that offers some of the best trail conditions.

• Hip Jump:  A jump that requires you to change direction midair.  

• Huck:  Riding a large jump or feature or trail that might be outside of your skill level.

I

• Involuntary Dismount:  A comical way of saying you crashed.

K

• Kicker:  A jump designed to give you plenty of airtime.

• Klunker:  A bike that is old that doesn't resemble modern bikes.  

L

• Ladder Bridge:  A wooden manmade section of trail.

• Lid:  Another name for a helmet,

• Line:   The path you take down the trail.  There can be multiple lines on some trails and most big features off an A line which goes over the feature and a B line that goes around the feature.  

• Lip:  The edge of a jump or landing.

• Loam:  A dirt with a lot of grip that gives great riding conditions and is great for roosting.

M

• Manual:  Another name for a wheelie and an essential beginner's skill to learn.   While riding you lift the front wheel off the ground and continue riding.  It can be used to help maneuver over some obstacles.  

• Mullet:  Oddly enough it is a bike that has a 29" tire in the front and a 27.5" tire in the back as opposed to the hair style in which the hair is longer in the back than the front.

O

• OTB (over the bars):  A crash that sends you over your handlebars.

• Over Cook:  When you are going to fast when you hit a jump and land farther than you wanted missing the downslope or landing area.  

P

• Pedal Strike:  When your pedal hits a rock or some other object which could result in crashing. Learning to ratchet your pedals can help avoid this.  When riding past larger rocks or logs you can see where other riders hit these. See Also Ratchet  

• Pinch Flat:  Sometimes called a snake bite, a pinch flat is caused when your inner tube gets pinched between the tire and the rim leaving small holes in the inner tube.

• Poach:  Illegally riding on a trail whether it's a trail that requires a fee to ride that you didn't pay or on a trail that doesn't permit biking.

• Pump:  A skill that allows you to gain speed without pedaling that resembles the motion of using a bicycle tire pump.  

• Pump Track:  A track that is designed with rollers, berms, and other features that allow the rider to keep momentum with little to no pedaling.  See Also Flow 

Q

• Qualifier:  A feature at the beginning of the trail that is designed to let you know if the features on the trail are within your skill level.

R

• Racing Strip:  The mud flung up your back from your back tire.  

• Rail:  Riding into a berm just right so you gain speed exiting the turn.

• Ratchet:  A pedaling technique in which you only partially pedal, resembling a ratchet on a bolt, to avoid pedal strikes. 

• Rock Garden:  A part of the trail that has a lot of rocks.

• Rock Roll:  A large rock that can be rode off without your tires leaving the ground

• Roller Coaster:  Commonly used on pump tracks it is a series of small bumps that you ride up and down

• Roost:  The dirt sand or snow that flies off your tire on a loose track.  It gets its name due to the fact it resembles a rooster's tail. 

S

• Scrub:  A skill used to get less airtime over a jump in order to keep your speed up.

• Session:  Re riding a trail or feature multiple times until you master it.

• Singletrack:  A mountain bike trail that is a little wider than the bike.

• Skinny:  Generally, a man-made feature that you ride on and is usually only a few inches wider than a tire. 

• Steezy:  When someone's riding looks stylish and easy. 

• Step Down:  A jump where the landing is lower than the take-off.  

• Step Up:  A jump where the landing is higher than the take-off.  

• Stoked:  A feeling of excitement

• Stomped:  Successfully landing a jump or cleanly completing a run.

• Stoppie:  The opposite of a wheelie, you apply front brake while leaning forward to bring the back tire off the ground.

• Switchbacks: Zig zags in the trail, normally 180 degrees, in order to make a steep climb or decent easier.

T

• Tabletop:  A jump with a flat surface between the takeoff and landing.  

• Taco:  When your rim gets bent in the shape of a hardshell taco.  

• Trackstand:  Another beginner skill where you stand on your pedals and remain balanced while moving as little as possible.     

W

• Wallride:  A technical trail feature that looks like a slightly curved wall that you can ride up like a berm.  

• Washout:  When you lose traction and your tires slide out to the side while turning or after landing a jump. 

Y

• Yard sale:  When you crash and all your loose gear like water bottles etc. scatters along the trail.