Get to know some mountain biking lingo - in no particular order. H/T to durangooutdoors.com

Endo - To be pitched off your mountain bike over the handlebars and front wheel.

Baby Heads - Rounded rocks that stick up on the trail creating a nice technical challenge.

Boulder Garden - Big rocks and boulders in the trail that you must ride around.

Chain Suck - Where your chain comes off the chain ring and gets sucked into the frame area usually in a nice bunch.

Clydesdale - A very large or obese rider.

Clean - To finish an entire trail or difficult section without stopping or putting your foot down. (See Dab)

Dab - This is where a rider has to put their foot on the ground when balance or momentum is lost.

Roadie - What mountain bikers call people that like to ride on paved surfaces.

Pogo - The action of a full suspension bike while peddling hard where the suspension bounces up and down.

Taco -This is what your wheel can look like if you smash it hard enough.

Fred - (Derogatory) A person that spends a ton of money on bike gear but cannot ride well.

Squishy - A full suspension bike.

HT - Hard Tail.

Niner - To have a bike with 29 inch wheels also known as a 29ner.

Cleanie - A person that likes to keep their bike clean and actively avoids mud or water crossings.

Squealing Pigs - This is where your disc brakes are glazed or worn and make tons of noise when applied.

Hammer - To ride hard and fast.

Hammer Head - A person that likes to ride hard and fast all the time.

Wang Chung - To hit ones crotch area on the top tube or headset, usually during a crash.

Winky - What mountain bikers call reflectors on a bike. (Nice winky "Fred".) 

Butter - Also known as buttery. This is when the trail is soft and smooth.

Chainring Tattoo - The grease mark that looks like part of a chainring either on the shin or calf.

Shark Bite - A step up from the chainring tattoo where the teeth of the chainring have chomped through the skin making wounds that look like a shark attacked. 

Corn Dog - What a rider looks like after crashing in soft sand or dirt, especially if sunscreen is being worn.

Crack Spackle - The line of mud that the back tire throws up ones back and butt.

Twot Gap - The bit of flesh showing when your arm or leg warmers slip down.

Train Track - A narrow and sometimes deep groove that has been worn into the trail that sucks your bike in and holds you in that section unless you stop. Usually found on steep sections and can be caused by too many riders locking up the brakes. 

Goo - An energy paste or gel that comes in a convenient plastic pack that you can squirt into your mouth for a refreshing yet disgusting energy boost. Sometimes called "Gooze" which is also the Persian word for "fart"… so if someone offers you some gooze before you bonk, politely pass on the offer.

Bonk - To exhaust your energy levels while riding up a steep grinder or trying to keep up with your hammerhead buddies causing you to stop on the trail.

Grinder - A long steep climb that you have to keep grinding your willpower in order to keep moving.