2000 Miler - A person who has hiked the entire distance between termini of the official (white-blazed) A.T., either by thru-hiking or section hiking.

A.T.C. - The Appalachian Trail Conservancy The Appalachian Trail Conference (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. ATC is both a confederation of Trail-maintaining clubs and an individual-membership organization.

AYCE  - 'All You Can Eat' Restaurants that offer all you can eat buffets are very popular with hungry hikers.

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 are a good place to find wild berries, they also attract much wildlife. A southern term.

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

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

Blazes - Painted, 2-inch by 6-inch, vertical white rectangles that are placed at eye height on trees and other objects, in both directions, to mark the official route of the Trail. 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 - A long-distance hiker who substitutes a section of blue-blazed trail for a white-blazed section between two points on the Trail.

Bounce box - A mail-drop type box containing seldom used necessities that is 'bounced' ahead to a town where you think you might need the contents.

Cat Hole - A small hole dug by a hiker for the deposit of human waste.

Data Book - Published for over 25 years by the ATC the Data Book is a consolidation of the most basic guidebook information into a lightweight table of distances between major Appalachian Trail shelters, road-crossings, and features--divided according to the guidebook volumes and updated each December to account for Trail relocations, new (or removed) shelters, and other changes.  

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

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.

Food Bag - A bag a hiker carries in their pack specifically for keeping all their food in. It is typically suspended from a tree at night so bears and varmints don't get into it. Also called Bear Bag.

Gear head - A hiker whose main focus is backpacking and outdoors gear.

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 worst nightmare.

GORP  - Good ole raisins & peanuts, or some other variation thereof.

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.

HYOH  - Hike your own hike, and not imitate someone else's.

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

LNT  - 'Leave No Trace', a philosophy and skill used to pass as lightly as possible when backpacking.

Mail Drop - Mail drops are a method of re-supply while hiking. A mail drop is usually made ahead of time, before the hike starts, and a person not hiking (usually a spouse or relative, but it can be a friend) 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.

Mountain Money - Toilet paper.

Mouse hanger - The cord with can contraption used to discourage mice from entering a pack when hung in a shelter.

Nero  - Almost a Zero ...in other words, a very short mileage day.

NoBo - Northbound thru-hiker, also a GAMEr (Georgia > Maine)

Privy - A trail side outhouse for solid waste. You shouldn't pee in the privy.

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".

Purist  1. A hiker who wants to pass every white blaze. 2. A hiker who wants others to pass every white blaze.

Register - A log book normally found at a trail shelter or a trail head. The original intent was for hikers to sign in so a searcher needing to find a lost hiker could tell where they last were.

Relo - A section of trail recently relocated.

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.

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.

Shuttle - A ride from town to trailhead, usually for a fee.

Skunked  - Failing to get a car to stop when hitch hiking.

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 thru-hiking without a backpack. Recently called "Freedom Packing".

Springer Mountain's summit - The southern terminus of the Appalachian Trail.

Springer fever - The almost uncontrollable urge to be back on the Trail that hits thru-hikers of past years each spring.

Stealth - A manner of camping where there is no indication that you are there, and no trace of your being there is left when you've left. Sometimes used as a term for camping illegally on public or private land.

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.

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.

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

The Whites - The White Mountains of New Hampshire, http://www.cs.dartmouth.edu/whites/at.html

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. Also what members of WhiteBlaze.net are called.

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

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