Hiking Glossary: 70+ Trail Terms Explained A–Z

New to hiking? Trail talk can sound like a foreign language — bonk, cowboy camping, PUDs, zero days. This glossary defines 70+ hiking and backpacking terms in plain English, A to Z. Bookmark it; you’ll need it.

Quick answer: This is a plain-English dictionary of 70+ hiking terms — from base weight and bear hangs to trail magic and zero days. Use the letter links above to jump to any term.

Jump to: A · B · C · D · E · F · G · H · L · M · N · O · P · R · S · T · U · V · W · Y · Z

A

Acclimatize — to let your body gradually adapt to high altitude over several days, reducing the risk of altitude sickness. Rush it and you’ll pay for it.

Altitude sickness (AMS) — illness caused by thin air at elevation: headache, nausea, dizziness. Our altitude sickness prevention guide covers symptoms and acclimatization strategy.

Approach trail — the (often long) trail you hike just to reach the “real” trailhead or route start.

AT (Appalachian Trail) — the ~2,200-mile footpath from Georgia to Maine, one of the world’s most famous long trails and the birthplace of much of this glossary.

B

Balds — treeless, grassy mountaintops in the southern Appalachians, prized for 360° views.

Base weight — everything in your pack minus consumables (food, water, fuel). The standard number ultralight hikers argue about. Find yours with the pack weight calculator.

Bear bag — food hung from a tree branch, away from your tent, so bears can’t reach it. Our bear safety guide explains the PCT hang method.

Bear canister — a hard-sided, bear-proof food container required in many national parks. Heavier than a bag, but bears can’t crush it.

Blaze — a painted mark on trees or rocks showing the trail route. Follow the blazes and you stay on trail.

Blue blaze — a side trail marked with blue blazes, usually leading to a viewpoint, shelter, or water source.

Blowdown — a tree fallen across the trail, typically from wind or storms. Expect to climb over or bushwhack around.

Bonk — to suddenly run out of energy mid-hike (“hitting the wall”), usually from not eating enough. Candy bars exist for this reason.

Bushwhack — to travel off-trail through vegetation, with no path to follow. Slow, scratchy, occasionally wonderful.

C

Cairn — a stacked pile of rocks marking the route, common above treeline where paint blazes won’t stick.

Cat hole — a 6–8 inch hole dug to bury human waste, per Leave No Trace practice.

CDT (Continental Divide Trail) — the ~3,100-mile trail along the Rockies from Mexico to Canada, completing the US Triple Crown with the AT and PCT.

Cowboy camping — sleeping in the open without a tent, just a sleeping bag under the stars. Glorious until it rains.

D

Daypack — a small backpack (roughly 10–25 liters) for hikes where you return the same day.

Difficulty rating — an easy/moderate/hard label (or 1–10 score) describing how demanding a trail is. Try our trail difficulty estimator to score any route.

Dispersed camping — camping outside developed campgrounds, usually free on national forest and BLM land, with no facilities.

Double blaze — two blazes stacked vertically warning of an upcoming turn or junction. The top blaze is offset toward the turn direction.

E

Elevation gain — the total vertical feet or metres you climb on a route (counting every uphill, not just the summit height). The number that actually predicts suffering.

Exposure — trail sections with steep drop-offs beside the path. “Exposed” means a slip would have serious consequences, even if the walking itself is easy.

F

False summit — a high point that looks like the top but hides the real summit behind it. The trail’s cruelest joke.

Fire road — a wide dirt road built for firefighter access, often used as a (dull but easy) hiking route.

FKT (fastest known time) — the speed record for a trail or route, tracked by the community at fastestknowntime.com.

G

Gap — Appalachian dialect for a mountain pass or low point between peaks (e.g., Newfound Gap).

Glissade — sliding down a snow slope on your boots, ideally controlled, ideally on purpose.

GPS track — a recorded breadcrumb trail of GPS points from a hike, shareable as a GPX file for navigation.

Green Tunnel — the AT’s nickname, for its long miles of enclosed forest walking.

H

Hammock camping — sleeping in a hammock instead of a tent, with a tarp overhead and an underquilt below for warmth.

Herd path — an unofficial, unmaintained trail worn in by hikers’ feet, common near popular summits and viewpoints.

L

Leave No Trace (LNT) — the seven principles of low-impact outdoor ethics: plan ahead, camp on durable surfaces, pack out waste, leave what you find, minimize fire impact, respect wildlife, be considerate. Full guide: Leave No Trace for beginners.

Lean-to — a three-sided open shelter common on the AT, first-come first-served.

M

Microspikes — lightweight traction chains that slip over boots for icy trails. Not crampons, not overkill — the shoulder-season essential.

N

Naismith’s rule — the 1892 formula for estimating hiking time: 1 hour per 3 miles plus 1 hour per 2,000 ft of ascent. See our data study putting it to the test and the hiking time estimator.

Nero — a “near-zero” day: a very short hiking day (a few miles) that still moves you forward, often into or out of a resupply town.

NOBO / SOBO — northbound / southbound: the two directions of a thru-hike. Most AT thru-hikers go NOBO from Georgia; PCT hikers split both ways.

O

Out-and-back — a route you hike out and then retrace, versus a loop or point-to-point.

P

PCT (Pacific Crest Trail) — the ~2,650-mile trail from Mexico to Canada through California, Oregon, and Washington.

Postholing — sinking knee- or thigh-deep into soft snow with each step. Snowshoes exist to prevent exactly this.

PUDs — “pointless ups and downs”: trail sections that climb and descend with no apparent reason. Hiker slang, usually muttered.

R

Ridgeline — the high crest connecting peaks; ridge walks offer the best views and the most weather exposure.

Route-finding — navigating where the trail is faint or unmarked, using map, compass, or GPS.

S

Saddle — the low dip between two peaks, shaped like a horse’s saddle. Also called a col.

Scramble — climbing steep rock using hands and feet, harder than hiking but easier than technical rock climbing.

Scree — loose, small rock fragments on a slope. Two steps up, one sliding step back.

Section hike — hiking a long trail in pieces over multiple trips, rather than as one thru-hike.

Shelter — a backcountry hut or lean-to for overnight stays, common on eastern US trails.

Slackpacking — hiking with just a daypack while someone shuttles your main gear to the next stop. All the miles, a fraction of the suffering.

Switchback — a zigzag turn that lets a trail climb steeply without going straight up the fall line. Cutting them destroys trails — don’t.

Summit — the top. The whole point.

T

Talus — large, loose rock slabs on a slope, bigger than scree. Hop carefully.

Ten Essentials — the classic must-carry safety list: navigation, headlamp, sun protection, first aid, knife, fire, shelter, extra food, extra water, extra clothes. Full breakdown: 10 essentials checklist.

Thru-hike — hiking an entire long trail end-to-end in one continuous trip.

Trailhead — where the trail starts, usually with a parking area and (sometimes) a privy.

Trail magic — surprise kindness from strangers: coolers of soda at road crossings, rides to town, grilled burgers at a gap. The AT and PCT run on it.

Trail name — the nickname thru-hikers earn or choose on long trails. Your real name stays home.

Trail register — the logbook at trailheads and shelters where hikers sign in. Useful for safety and for finding friends ahead.

Traverse — crossing a slope sideways, or a route that crosses a mountain range rather than climbing straight over.

Treeline — the elevation above which trees stop growing. Above it: big views, big weather.

U

Ultralight — a backpacking philosophy (and community) obsessed with cutting pack weight, usually defined as a base weight under 10 lb (4.5 kg).

V

Vista — a viewpoint, often named on maps in the eastern US (“Cooper’s Vista”).

W

Water cache — water stashed ahead of time on dry routes, or left by volunteers (“trail angels”) for desert hikers. Desert logistics: how much water for desert hiking.

White blaze — the AT’s official marker: a 2×6 inch white paint stripe. Follow the white blazes from Georgia to Maine.

Wilderness area — federally designated land with no roads, motors, or bikes. Foot and horse travel only.

Wild camping — camping outside designated sites. Legal in many places with Leave No Trace care; restricted or banned in others — always check local rules.

Y

Yellow-blazing — skipping trail miles by hitchhiking or driving (following the yellow road lines). Thru-hiker slang, mildly scandalous.

Yo-yo — hiking a long trail end-to-end and then turning around and hiking it back. Twice the miles, twice the legend.

Z

Zero day — a rest day with zero trail miles, usually in a town with a shower, laundry, and a burger.

Frequently asked questions

What does thru-hike mean? Hiking an entire long-distance trail end-to-end in one continuous trip — e.g., all ~2,200 miles of the Appalachian Trail in a single season.

What is base weight? Everything in your pack except food, water, and fuel. Calculate yours with the pack weight calculator.

What do NOBO and SOBO mean? Northbound and southbound — the two directions of a thru-hike on the AT, PCT, or CDT.

What are the Ten Essentials? Navigation, headlamp, sun protection, first aid, knife, fire starter, shelter, extra food, extra water, extra clothes. See the full checklist.

What is trail magic? Unexpected kindness from strangers — drinks at road crossings, rides to town, surprise meals. A beloved long-trail tradition.

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Bloggers and hiking clubs: embed this “10 terms beginners always confuse” card with attribution:

<div style="border:2px solid #2d5a3d;border-radius:.8rem;padding:1.2rem;font-family:system-ui,sans-serif;max-width:34rem;">
  <strong>🥾 10 hiking terms beginners always confuse</strong>
  <ol style="margin:.6rem 0;">
    <li><b>Base weight</b> — pack minus food, water &amp; fuel</li>
    <li><b>Bonk</b> — sudden energy crash from under-eating</li>
    <li><b>Cairn</b> — stacked-rock route marker</li>
    <li><b>False summit</b> — looks like the top, isn't</li>
    <li><b>Nero</b> — a near-zero-mile day</li>
    <li><b>Slackpacking</b> — daypack only, gear shuttled ahead</li>
    <li><b>Switchback</b> — zigzag climb (never cut them)</li>
    <li><b>Trail magic</b> — surprise kindness from strangers</li>
    <li><b>Treeline</b> — elevation where trees stop</li>
    <li><b>Zero day</b> — a rest day, zero miles</li>
  </ol>
  <p style="margin:0;font-size:.85rem;"><em>Full A–Z: <a href="https://trailtested.pages.dev/trails/hiking-glossary-a-to-z/">Hiking Glossary — Trail Tested</a></em></p>
</div>

Keep learning: Naismith’s rule vs real hiking speeds (data study) · estimate any trail’s difficulty · Leave No Trace basics