Every trade runs on a private vocabulary, and nobody teaches it. You pick it up by hearing a word four times and inferring the meaning, or by asking and being told "you'll figure it out."
This is the shortcut. Six trades, about sixty terms, in plain language. It is written for three people: the apprentice in her first month, the partner or parent trying to buy a gift that gets the word right, and anyone who has been nodding along in a huddle for two weeks.
Regional variation is real. Two locals forty miles apart will disagree about half of this. Take it as a starting point, not a ruling.
Everybody — general jobsite
Turn out — to complete an apprenticeship and become a journeyman. "She turns out in June." The single most important milestone in the first decade of a trade career; we wrote about it in Turning Out.
Top out — same idea in some trades and locals: reaching the top apprentice wage step, or finishing the program. Ask locally which one it means.
Journeyman — a fully qualified tradesperson who has completed an apprenticeship. Note: many tradeswomen call themselves journeymen and dislike being corrected to "journeywoman." Others prefer journeywoman. Use whatever she uses. This is the single most common way outsiders get the language wrong.
Local — the numbered branch of a union. "Local 48." Often used as identity shorthand: where you were trained and who you work with.
JATC — Joint Apprenticeship and Training Committee. The body that runs a union apprenticeship program.
Gang box — the big lockable site toolbox. Also where the stickers go.
Green hat — a new apprentice, from the practice on some sites of color-coding hard hats by experience.
Punch list — the list of remaining defects and unfinished items before a job is signed off.
Rough-in — the first-fix stage: everything that goes in before the walls close. Followed by trim or finish.
Trim out — the second-fix stage: devices, fixtures, plates, everything visible.
Layout — marking where things go before installing them. Getting layout wrong is expensive; getting it right is invisible.
Hot work — any task producing sparks or flame. Usually requires a permit.
Lockout/tagout (LOTO) — the procedure for isolating and locking an energy source before working on equipment. Not slang. It is the difference between a normal day and a fatality.
Toolbox talk — the short safety briefing at the start of a shift.
Scope creep — work added to a job without being added to the contract.
Work purse — self-deprecating name for the tool bag. Used affectionately.
Electrical
Wireman / inside wireman — an electrician working commercial and industrial interiors. The classification most union electrical apprentices train in.
Conduit — the pipe electrical conductors run through. Bending it well is a craft, and the first clean bend is a genuine milestone.
Bender — the tool used to bend conduit. Hand bender, hydraulic bender, or a benchtop electric.
Stub-up — a 90-degree bend where the conduit comes up out of a floor or slab.
Kick — a small offset bend, used to move a run slightly around an obstruction.
Dog leg — an unintentional twist in a bend, so the conduit no longer lies flat. Nobody wants dog legs in their run.
Pull — running conductors through installed conduit. "We're pulling tomorrow" means a long day.
Fish tape — the flexible tape pushed through conduit to pull the wire back.
Terminate — to connect a conductor to a device or lug. "Terminated the panel."
Make up — to join and dress conductors in a box, ready for devices.
Dress — to arrange conductors neatly. A well-dressed panel is a point of pride and instantly readable to another electrician.
Homerun — the cable running from the first device back to the panel.
Megger — an insulation resistance tester; also used as a verb.
Sparky — an electrician. Affectionate, used within the trade.
Welding
TIG (GTAW) — gas tungsten arc welding. Slow, precise, the process most associated with high-skill work.
MIG (GMAW) — gas metal arc welding. Faster, higher deposition, the production process.
Stick (SMAW) — shielded metal arc welding. Runs in wind and on dirty material; the field process.
Bead — the deposited weld metal itself.
Stack dimes — laying a TIG bead with even, overlapping ripples that look like a stack of coins. The visual shorthand for good hand control, and the phrase most likely to appear on a welder's shirt.
Root pass — the first pass in a multi-pass joint, at the bottom of the groove. The hardest one and the one that determines whether the joint is sound.
Cap — the final pass, the one people see.
Hood down — the moment the helmet comes down and the work starts. Used as a mindset: heads down, focused.
Undercut — a groove melted into the base metal beside the weld and not filled. A defect.
Porosity — gas trapped in the weld. Another defect, usually from contamination or a shielding problem.
Prep — grinding and cleaning the joint before welding. Most welding quality is decided here.
Tack — a small temporary weld holding parts in position.
Certification / cert — a qualification to weld a specific process, position and material. Certs are the currency of a welding career.
6G — a pipe welding test position: fixed pipe at 45 degrees, welded all the way around. The hard one.
Carpentry
Plumb, level, square — vertical, horizontal, at right angles. The three conditions everything is checked against, and the closest thing carpentry has to a creed.
Scribe — to mark a workpiece to match an irregular surface so it fits without a gap. What separates finish work from framing.
Reveal — the deliberate small setback between two surfaces, so a joint reads as intentional.
Proud — sitting slightly above the surrounding surface. Usually a problem. The opposite is shy.
Dovetail — an interlocking joint. Slow, strong, and a signature of hand work.
Hand plane — for the last fraction of a millimeter, where a machine cannot go.
Blocking — extra framing added between studs to provide fixing points later.
Rip / crosscut — cutting with the grain / across it.
Sawdust — the thing that gets into everything, forever, including your car and your washing machine.
Snipe — the divot a thickness planer leaves at the start or end of a board.
Plumbing
Rough-in — same idea as electrical: everything in the walls and under the slab before they close.
Stack — the main vertical drainage pipe.
Trap — the U-bend holding water to block sewer gas.
Vent — the pipe letting air into the drainage system so traps do not siphon dry.
Sweat — to solder a copper joint. "Sweating fittings."
Press — a mechanical fitting crimped rather than soldered. Faster, and the subject of ongoing trade arguments.
Snake / auger — the tool for clearing a blockage.
Backflow — reverse flow of contaminated water into a clean supply. Preventing it is a licensed specialty.
Nipple — a short threaded pipe section. Yes, everyone made the joke once. Nobody is still making it.
Fall — the slope on a drain line. Not enough fall and it does not drain; too much and the solids get left behind.
HVAC
Superheat — how much hotter the refrigerant vapour is than its boiling point at that pressure. A core diagnostic number.
Subcool — the mirror measurement on the liquid side. Between them, superheat and subcool tell you what a system is actually doing.
Charge — the refrigerant in the system, and the act of adding it.
Static pressure — the resistance in a duct system. High static pressure is why a system is loud and inefficient.
Delta T — the temperature difference across a coil.
Air handler — the indoor unit moving air across the coil.
Condenser — the outdoor unit rejecting heat.
Reversing valve — what lets a heat pump run in both directions.
Micron gauge — measures the vacuum during evacuation. Skipping this step is how you get a call-back.
On-call — the rotation. In Phoenix in July, on-call is the whole personality of the month.
A note on how these words get used
There is a difference between using trade vocabulary and performing it.
Merchandise fails when it stacks four terms into a slogan that no working person would say out loud. It works when it uses one word correctly, the way it is actually used — which is usually flat, specific, and without explanation.
That is the rule we design to: our collections start from one word per trade, used the way the trade uses it, and stop there.
If you are buying for someone and you now have the word but not the product, our gift guide covers what actually gets worn.
Missing a term, or does your local use one of these differently? Send it to us — this glossary gets updated, and regional corrections are the most useful mail we get.