Here are over 75 terms that thru-hiker's use on the Appalachian Trail. Some are just slang expressions and others are more technical gear terms. Let us know what we missed!
| AMC | Appalachian Mountain Club. Mainly known as the organization in charge of the hut system in the White Mountains. |
| Alpine Zone | Also known as 'above the treeline'. The high-elevation areas where trees are unable to grow. |
| AT | Appalachian Trail |
| ATC | Appalachian Trail Conservancy. Non-profit organization in charge of protecting and maintaining the Trail. |
| Awol | 'The A.T. Guide'. The only map a thru-hiker needs. |
| Balds | Barren areas on many mountain tops. Their existence is mostly a mystery. |
| Base Weight | Total Pack Weight - Consumables (food, water, etc) = Base Weight |
| Bear Bag | Hung in a tree to prevent attracting any bears. Usually contains food, trash, toiletries - anything with a strong odor. |
| Biner | Short for 'carabiner' - the metal loop with a spring loaded opening generally used for ropes. |
| Bivy | Short for 'bivouac sack' - a mini tent-like shelter. |
| Bladder | Or 'water reservoir'. Smaller collapsible water container. |
| Blaze | Used to mark the Trail. Typically a 2 x 6 inch strip of paint on a tree located near eye level. |
| (Aqua) Blazing | Taking a waterway instead of the Trail. |
| (Blue) Blaze | The blaze that leads to a water source. |
| (Pink) Blazing | Hiking with a female. |
| (Yellow) Blazing | Driving to the next trail head and essentially skipping a chunk of hiking. Opposite of 'purist'. |
| (White) Blaze | The iconic blaze that marks the Appalachian Trail. |
| Bluff | Steep cliff. |
| Bounce Box | Box of supplies you ship or 'bounce' forward to pick up in your next trail town. |
| Bushwhacking | Hiking off trail. Done for the adventure of it or because you are lost. |
| Cache | Hiding place. Typically where you or a trail angel would stash food and other goodies. |
| Camel Up | Drinking as much water as possible at a water source to prevent from carrying it. |
| Cairn | Pile of rocks or stones to mark the trail. Used instead of a blaze if there are no trees. |
| Cathole | Hole in the ground dugout for human waste. Ideally at least 6 inches deep and at least 200 feet away from a water source. |
| Contour Lines | Lines used on a topographical map to display variations in elevation. |
| Cowboy Camping | Camping underneath the stars without a tent. |
| Cowboy Coffee | Mixing water with unfiltered coffee grounds. |
| Crampons | Metal frame used on boots for traction in snowy and icy conditions. |
| Cuben Fiber | High-performance fabric, also known as "Dyneema", used as an ultralight material for some tents and bags. |
| DEET | Ingredient used in insect repellents - also known as 'diethyltoluamide' |
| Double Blaze | Two blazes aligned vertically to signal a sharp turn in the Trail. |
| Dromedary Bag | Large collapsible water container. |
| Droppin' Trout | Process of pulling down your pants. Generally shouted as a warning to other hikers in the shelter that you are about to change clothes. |
| False Summit | Sense of approaching the summit and then realize it is only a small plateau. |
| FKT | 'Fastest Known Time'. The speed record held for completing the Appalachian Trail either 'supported' or 'unsupported'. |
| Flip-flop | Thought of as hiking the Trail in two separate 'halves' instead of one continuous stretch. Ex: ME>VA and then GA>VA or VA>GA and then ME>VA. |
| Footprint | Separate 'floor' of your tent used as a groundcloth or additional protective barrier. |
| Gaitors | Leggings used to protect your shins and ankles from thick brush or prevent water from draining into your feet. |
| Gap | Low spot on a ridge line in between mountains. |
| GORP | "Granola, Oats, Raisins and Peanuts" or "Good Ole Raisins and Peanuts". Also called 'Trail Mix'. |
| Green Tunnel | The Appalachian Trail. Referring to the heavily wooded green forests that the Trail snakes through. |
| Guylines | Chord or rope used to tie down the tent or tarp. |
| Hiker Box | Box of freebies. Generally leftover food or gear from previous hikers located in hostels or shelters. |
| Hiker Trash | Tongue-and-cheek term for thru-hikers. After a week on the Trail, we have been (proudly?) known to resemble vagrants. |
| Huts | Large cabins mostly associated with being in the White Mountains and organized by the ATC. |
| HYOH | 'Hike Your Own Hike' expression. |
| Kinlin | Small firewood used to ignite a fire. |
| Knob | Small mountain or rounded hill. |
| Hostel | Trail town lodging. Like a hotel with bunk beds. |
| Lean-to | Simple shelter structure comprised of a roof angled at a 45 degrees. Generally only has 3 walls. |
| Logbook | Also know as 'register'. Every shelter has one. Used as a record for safety of last known location. Also used to communicate with other hikers and vent about anything and everything. |
| NERO | "Near Zero" day. Hiking only a mile or less. |
| NOBO | Northbound hiker. Georgia to Maine. |
| Pocket Rocket | Trademarked named for an MSR stove. Has become a generic term for a small foldable canister stove top. |
| Postholing | Process of stepping in snow and leaving a hole. |
| Privy | Bathroom at a shelter. Most of the time a simple wooden outhouse with a composting toilet hole. |
| PUDs | 'Pointless Ups and Downs'. Referring to the rolling nature of the trail. |
| Ridge-runner | Somewhat like an informal Park Ranger. Generally a volunteer interested in promoting respect for the Trail. |
| Scramble | Type of 'hands and knees' hiking in steep or rocky sections where walking is not an option. See Mihousac Notch. |
| Section Hiker | Someone who hikes the Appalachian Trial in sections over a longer period of time than a continuous thru-hike. |
| Shelter | Simple wooden structures scattered every 10-20 miles along the entire Trail. Most hold around 8-12 hikers. |
| Slack Packing | Not carrying gear for the day. Generally this means leaving gear in town and getting shuttled to Trailhead A in the morning and picked up at Trailhead B in the afternoon. |
| SOBO | Southbound hiker. Maine to Georgia. |
| Stealth Camping | Camping in a site that has not been used as a campsite before. |
| Switch Back | Used to zig-zag and lengthen the trail for a more moderate incline instead of hiking straight up a very steep incline. |
| Thru Hiker | One who hikes the Trail in one continuous run or within a year time frame. |
| Townie | 'Dayhikers', 'Bathers' or people from town. |
| Trailhead | Where a section of trail begins. Usually at a road crossing. |
| Trail Angel | Giver of Trail Magic. A volunteer who helps hikers with a place to stay in their house, a shuttle to the trail head, free food, anything. |
| Trail Magic | Given by Trail Angels. The goodies a Trail Angel offers out of goodwill. |
| Trail Name | Name a hiker goes by on the Trail. A sort of 'alter-ego'. Almost all hikers go by a trail name. |
| Treeing a Bear | Act of surprising a bear and it sliding down a tree. |
| Triple Crown | Three major USA hiking trails: The Appalachian Trail, The Pacific Crest Trail, The Continental Divide Trail. One who completes all three is known as a 'Triple Crowner'. |
| UL | 'Ultralight'. A minimalist backpacking mentality. |
| Vestibule | Porch of a tent. |
| Widowmaker | Dead tree waiting to fall and make a widow out of the unsuspecting hiker's wife. |
| Webwalking | Taking the lead for the group and walking through all of the fresh spider webs. |
| Work For Stay | Instead of paying for a room, at select hostels and huts, many hikers choose to work or volunteer for a few hours. |
| ZERO Day | Lazy and luxurious days of hiking zero miles. |
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