Hiking and the Appalachian Trail has its own terms:

AT - the Appalachian Trail.

ATC - Appalachian Trail Conservancy. The ATC is a volunteer-based, private, nonprofit organization dedicated to the preservation, management, and promotion of the Appalachian Trail as a primitive setting for outdoor recreation (on foot) and for learning and is both a confederation of Trail-maintaining clubs and an individual-membership organization.

Bald - a low elevation mountain surrounded by forest yet devoid of trees on the crown. Typically covered with meadows, balds can offer great views and also attract much wildlife. A southern term.

Bear Bag - bag used by hikers to hang their food out of reach of bears and other animals.

Bear Cable - permanent cable rigged high between two trees for hanging bear bags.

Blazes - painted, 2-inch by 6-inch, vertical white rectangles that are placed on trees, rocks and other objects, in both directions, to mark the official route of the AT. Side trails are marked with blue blazes. You see horizontal, diagonal, arrows, and other blazes along the Trail.

Blue Blaze - spur trails off the AT to bad-weather routes, views, shelters, water sources, etc are often marked by AT style blazes painted blue.

Blue-Blazer - long-distance hiker who substitutes a section of blue-blazed trail for a white-blazed section between two points on the AT.

Bonus Miles - miles hiked due to getting lost, taking the wrong turn, and hiking into or out of towns off the trail.

Cairn - a stack of rocks used on some trails for directional purposes but mostly on the AT as a memorial.

Double Blaze - two blazes, one above the other as an indication of an imminent turn or intersection in the trail. Offset double blazes indicate the direction of the turn by the offset of the top blaze.

End-to-Ender - an alternative term for 2,000-Miler.

Flip-Flop - a term used to signify a hiker that starts hiking in one direction then at some point decides to jump ahead and hike back in the opposite direction. Some hikers on the AT will start hiking northbound from Springer Mt. and usually at Harpers Ferry they may decide to go to Katahdin and hike back down to Harpers Ferry, thus completing their thru-hike. This is a good way for someone to still get their hike completed if they are behind and their time is limited due to the oncoming winter.

GAME or GAMEr - a hike or hiker going from Georgia to Maine.

Gap - a southern term for a low spot along a ridge line, called a col by northern individuals.

Gear Head - A hiker who is passionate about backpacking and outdoors gear (i.e. GramCracker is a self-proclaimed "Gear Head").

Giardia - more properly known as giardiasis, an infection of the lower intestines cause by the amoebic cyst, Giardia lamblia. Giardia resides in water so it is wise to always chemically treat or filter your water before drinking. Symptoms include stomach cramps, diarrhea, bloating, loss of appetite and vomiting. Also know as, a backpacker’s (or from O'Brien family experience... cross country runner training in the mountains (right Shea?)) worst nightmare.

GORP - “Good ole raisins & peanuts”, or some other variation thereof. Also known as Trail Mix.

Ground Control or Trail Support - hiker support that handles the 'real world' concerns like bills and pets, and mails a hiker packages (and in the case of "Five Pair" most refer to him as "Jim").

Harpers Ferry - the ATC's national headquarters and information center is located in Harpers Ferry West Virginia, about 1000 AT miles north of Springer Mountain. A short blue blazed trail leads to the headquarters, where AT hikers traditionally sign the register and have their photo taken. This is the psychological halfway point on the AT.

Headlamp - a small flashlight attached to a band or strap and worn on the head.

Hiker Box - a cabinet or box at hostels where hikers donate unwanted food for the hikers coming behind them.

Hiker Midnight - 9:00pm and given the work rate of the hikers during the day, most are asleep by that time.

Hiker Porn - the Weather Channel.

Hostel - an establishment along the trail that has bunks, showers, and sometimes cooking and mail drops, for AT hikers.

Hydration System - an 'improvement' on drinking out of a bottle, consists of a plastic bladder, hose, and mouth piece/valve that allows hands free drinking.

Katahdin - the AT's northern terminus is at Baxter Peak on Maine's Katahdin. Katahdin is a Penobscot Indian word meaning "Greatest Mountain."

Knob - a prominent rounded hill or mountain. A southern term.

LASH or Lasher - LASH and Lasher is a relative new term which is used to describe a hiker undertaking a thru hike and a section hike. L.A.S.H is an acronym for "Long Ass Section Hiker".

LNT - "Leave No Trace", a philosophy and skill used to pass as lightly as possible when backpacking. It also means that you pack-out all your trash and leave no visible signs that you were there.

MacGyver - based on the old TV show where the hero would construct useful devices out of common materials. To hikers it means to build or repair gear with imagination.

MacKaye, Benton - Benton MacKaye (rhymes with high, not hay) is the man who in 1921 proposed an Appalachian Trail as the connecting thread of a 'project in regional planning." MacKaye envisioned a trail along the ridge crests of the Appalachian Mountain chain from New England to the Deep South, connecting farms, work camps, and study camps that would be populated by eastern urbanites needing a break from the tensions of industrialization.

Mail Drop - mail drops are a method of re-supply for hikers. A mail drop is usually made ahead of time, and a person not hiking (usually Ground Control) mails the package according to a pre-arranged schedule so that it arrives on time for the hiker to receive it at the post office.

Maintainer - a volunteer who participates in the organized Trail-maintenance programs of the ATC and its member clubs.

MEGA or ME-GA - a hike or hiker going from Maine to Georgia.

Mountain Money - toilet paper.

Mouse Hanger - a 12”-18” length of cord run through a tin can with a small stick tied to the end. Hung from a beam in the shelter, a hiker will hang his/her pack on the stick. Mice, attempting to climb down the rope to get into the pack are deterred by the tin can.

Nero - almost a zero ...in other words, a very short mileage day.

NoBo - northbound thru-hiker, also a GAMEr (Georgia to Maine).

Platinum Blaze - enjoying hotels and restaurants along the trail vs. tents and trail grub.

Privy - a trailside outhouse for solid waste.

PUDS - thru-hiker shorthand for "pointless ups and downs", referring to the less interesting sections of mountains thru-hikers encounter from time to time; several PUDS in a row are MUDS, which is shorthand for "mindless ups and downs".

Puncheon - (also called a bog bridge) is a wooden walkway built to provide a stable, hardened tread-way across bogs, mud flats, and marshy areas.

Purist - A hiker who makes a point to hike past every single white blaze and/or carry a backpack for the entire distance. No slackpacking or blue-blazing allowed for these folks! "Five Pair" is a purist.

Relo - a section of trail recently relocated. Thus, the variation in AT distance from year to year. The trail measured 2,168.1 miles in 2001 and 2,184.4 in 2012. The total distance of the trail changes slightly from year to year as trail maintenance groups reroute the trail as needed.

Ridge Runner - a person paid by a trail-maintaining club or governmental organization to hike back and forth along a certain section of trail to educate hikers, enforce regulations, monitor trail and campsite use, and sometimes perform trail maintenance or construction duties. Such persons are most often found in high-use areas of the trail.

Section Hiker - a person who is attempting to become a 2,000-Miler by doing a series of section hikes over a period of time.

Shaffer, Earl - Earl Shaffer 1918-2002 "The Crazy One," the first person to thru-hike the Appalachian Trail. Poet, WW2 veteran, author of 'Walking With Spring,' and 'The Appalachian Trail, Calling Me Back To The Hills,' and three time thru-hiker, northbound in 1948, southbound in 1965, and northbound again at age 79, 50 years after his first hike. http://www.earlshaffer.com/

Shelter - a three sided wooden or stone building, spaced out a half day's hike apart, near a water source, and with a privy. The AT has many kinds of shelters, from barns to cabins.

Slackpacking - a hiking term coined in 1980 to describe an unhurried and non-goal-oriented manner of long-distance hiking (i.e., slack: "not taut or tense, loose"), but in recent years has been used to refer simply to hiking or thru-hiking without a backpack. Can be used as a derogatory term by those carrying their backpacks.

SoBo or Southbounder - a hiker who is hiking the AT from Maine to Georgia. A small minority of hikers actually hike this direction, primarily because of black flies.

Springer Mountain - the summit is the southern terminus of the Appalachian Trail.

Stile - steps constructed over a fence to allow people, but not livestock, to pass.

Swag - the lowest connecting point between two ridges in the South.

Switchback - a method of building a trail that forms a zig-zag across the face of a mountain. The strategy is to prevent erosion and to make the climb easier. Switchbacks are not made to be short cutted, although some people do, which damages trail. Switchbacks are often appreciated by hikers.

Thru-Hiker - traditionally a person who is attempting to become a 2,000-Miler in a single, continuous journey leaving from one terminus of the Trail, and backpacking to the other terminus.

Trail Angel - someone who provides unexpected help or food to a hiker (i.e. GramCracker to Terri).

Trailhead - where the trail leaves a road crossing or parking lot.

Trail Magic - unexpected, but welcome, help or food.

Trail Name - a nickname adopted by or given to a hiker. This name is used almost exclusively when communicating with others on the trail and in trail register entries.

Trail Runner - a person who runs the AT, as opposed to walking it. The current speed record for a "supported" (someone to provide food and support) thru-hike of the AT was set by Karel Sabbe 41 days, 7 hours, 39 minutes (averaged 53 miles per day). The self-supported AT record is 45 days, 12 hours, 15 minutes, set by Joe “Stringbean” McConaughy in 2017.

Tour Hiker - a person who pretends to be hiking the entire AT, as a thru-hiker, but instead skips sections and usually looks for ways to spend more time lounging in towns and less time hiking the AT; usually scoffs at the traditions of thru-hiking and thinks that the phrase “hike your own hike” is an excuse for just about anything.

Ultra Light - a style of gear or hiking that focuses on using the lightest gear possible.

Vitamin I - ibuprofin is an over the counter anti-inflammatory drug that many hikers use while backpacking.

Webface or Web Master - what happens to the first person on the trail each morning – they clear away all the spider webs across the trail with their face.

The Whites - the White Mountains of New Hampshire.

Whiteblazer - a term from the Appalachian Trail to describe a person hiking pure (see purist), that is, hiking past every white blaze - which are the standard trail markers on the AT.

Yellow Blazers - a reference to yellow road stripes derogatorily given to those who hitchhike to move down the trail.

Yogi-ing - You know... the cartoon bear. The good-natured art of "letting" food be offered cheerfully by strangers without actually asking them directly (If you ask, it's begging!).

YMMV - “Your Mileage May Vary”, hiker jargon for “this worked for me, but your results/opinions might not be the same.”

Yo-Yo-ing - the act of completing one A.T. thru-hike, then immediately turning around to begin another in the opposite direction.

Zero Day - a day in which no miles are hiked, usually because the hiker is stopping in a town to re-supply and/or rest.