Does anyone know of a 40K glossary or list of commonly used terms? I've read a lot of Black Library books and know the basics but I thought a comprehensive list of terms would be nice to go over with new players.

On a side note I'd like to try my hand at some 40K style short stories so something like this would be of immense help in the writing department!

I wanted the same kind of thing but never found much. I've compiled a list that I keep in a doc for myself, though I totally forget where I grabbed most of these. I know I had a source that I've added too, just can't remember. Here you go:

ABDUCTOR — This variation, or pattern, of the standard Rhino chassis carries prisoners for the Adeptus Arbites.
ABLUTORY — A rest room or water closet, which often includes shower
ACTUALITY SPHERE — A holographic sphere used to display current status
AGRI-PLEX — A farming complex of moderate to large size
AIR-MILL — (Also: Airmill) A fanned structure, either used to push air, such as the massive ones used in hives, or to capture the wind to do work, such as flour mills on more primitive planets.
AMASEC — This fine liquor is common through much of the Imperium.
AMPLIVOX — This is a sound amplification device.
APOTHACARION — Though this term also refers to medical facilities in general, it specifically references the facilities and gene-seed repositories of Space Marine Apopthecaries.
ARCHEOXENOLOGY — The study of xenos artifacts
ARCHEOTECH — This term represents either technology or materials from better times. It can consist of copper wiring in the underhive or machines from the Golden Age of Technology depending on the hunter.
ASH-SLEEP — This term refers to the state some psykers and astropaths enter when they have burnt out.
AUGER — A remote sensing device, often part of a defensive network
AUSPEX — This is a common name for many types of ranged sensory equipment, from radars to bio-detectors. Most have the capacity to detect life forms, energy sources, and large concentrations or metal or other elements. They range from handheld models to the main sensoriums on starships
AUTOVOX — This term refers to a vox transmission sent by a machine spirit, such as an automated countdown.

BINARY CORTEX — This term refers to the Mechanicus practice of linking two brains to the same body. This can result in psychological difficulties.
BIO-ERROR PURGATION — This Adeptus Mechanicus term refers to reprogramming.
BIOLUMIN — A means of lighting utilizing bioluminescence
BLINDER — Navigators use this somewhat derogatory term to refer to those without Warp sight.
BLUIES — Some Imperial citizens use this derogatory term to refer to the Tau.
BLUNT — Psykers use this slightly derogative term to refer to non-psykers.
BULK-LIFTER — These large starships carry bulk goods from planet to planet

CADUCAL HELIX — One of the holy symbols of the Adeptus Mechanicus
CAFFEINE — (Also: Caf, Caff, or Recaf) Any of a number of coffee-like drinks that contain caffeine
CARGO-# — These are large, wheeled trucks, named for their number of wheels. Thus, a ten-wheeled vehicle would be called a Cargo-10.
CENOBYTE — These servitors assist Space Marine Chaplains or high-ranking officials of the Ecclesiarchy
CHIRUGEON — A doctor or surgeon
CHIRUMEK — A chaos doctor practicing the fusion of biological and mechanical components
CHRON — (Also: Chronograph) This shortened form of chronograph means watch; thus wrist-chron or pocket-chron are also popular terms.
COGBOY — Some members of the Imperial Guard - and certain portions of the populace - use this mildly derogatory term in reference to Engineseers and Tech Priests of the Adeptus Mechanicus.
COGITATION BANKS — See Cogitator.
COGITATOR — A computer, from suitcase-sized to the main core and stacks of a starship or installation
COUNTERSEPTIC — (Also: Counter-septic) Any of a number of antiseptic liquids
CRYO-BIN — A cold-storage unit for suspended animation
CRYOGENERATOR — These machines supply the necessary temperature for Hibernation berths.
CRYO-STACKS — An array of cryo-bins, usually on a starship
CYCLE — Those on starships or in the depths of hives use this term to refer to a day.

DATA-ARC — These objects hold large amounts of data, es40sentially a mini-library.
DATA CRYSTAL — These are data storage devices, approximately the size of an almond, that can be encrypted.
DATA-LOOM — A large, powerful cogitator
DATA-SLATE — These boards hold and display moderate amounts of data.
DATASLAVE — A type of Adeptus Administratum worker.
DATA-SLUICE — Cables that carry large volumes of data
DRONE — This is a common term for crude servitor-skulls and other small, semi-autonomous servitors.

ELECTRO-CANDLES — Small electric lights
EMPEROR'S GRACE — This term refers to killing one who is mortally wounded to save them suffering.
EPIMA-OIL — A scented oil

FABRICATORY — A manufactorium
FARCODER — These spy devices send the content of a data-line to a third party.
FLUX-UNIT — A power conversion source.

GLOW GLOBES — General term for artificial lighting
GRAV CHUTE — An anti-gravity device that works as a parachute, to slow the fall of an individual or ordnance

HAB-BLOCK — (Also: Habs) This is the common name for any mass-housing complex in Imperial cities.
HOLO — This term is both a shortened version of Hololith and a general reference to entertainments using it as a medium.
HOLOLITH — A holographic viewer, essentially a three dimensional pict screen for watching newscasts or entertainment

IMMATERIUM OBSERVEATORY — These bubbles on the experior of Warp vessels allow Navigators or, when properly shielded, others to view the Empyrean while in the Warp.
INDENTS — Common Imperial slang for indentured workers
INCARCERY — Prison or jail, frequently one of the Adeptus Arbites

LHO-STICK — A popular Imperial narcotic, much like a cigarette, made of a rolled paper tube containing a scented plant-derived substance.
LIFTER — This term refers to any planet-to-orbit craft for moving cargo or personnel.
LOGEUMS — A performance stage
LOGIC MILL — This name is given to large, powerful cogitators.
LOW ANCHOR — This naval term refers to starships in low orbit, or in the case of airless bodies those stationed closest to the asteroid, etc.
LUMIN-PANEL — This generic term refers to any light-generating panel.

MAGLEV — Trains on technologically advanced worlds still use magnetic levitation for trains and cargo transports.
MAGLOCK — This security system for doors is an advanced form of lock, using a magnetic mechanism rather than mechanical tumblers
MANUFACTORIUMS — Factories
MEATBAG — The Adeptus Mechanicus use this term as an insult to the unaugmented.
METRICULATOR — A large computer

NULL-SHIP — These psychically shielded ships of the Inquisition are used to probe chaos worlds in the Eye of Terror or Maelstrom.

OPTICON — A remote camera or visual sensor. The Imperial Navy has opticon stations near the Warp points of key systems.

PICT — This is the common name for any artificial image, usually displayed upon a screen, but sometimes in hardcopy as well.
PICT-CAST — This is a remote view of an event either transmitted live or recorded.
PICT-SCREEN — This is any of a variety of technologies used to display images.
PLASMA COIL — This element is integral to the power systems of starships.
PROMETHIUM — This general term covers most flammable fuels derived from crude promethium in the Imperium. It is used as a fuel for most Imperial vehicles, and in weapons such as flamers. It is also essential in the production of plastics and synthetic materials, as well as certain drugs and dyes.

REGICIDE - Basically the game of chess. Often played by nobles and the elite; though not uncommon for Space Marines to play.

SECTOR — This Imperial division of space is approximately 200 light-years to side, containing anywhere from roughly 4 to 12 subsectors depending on stellar density.
SIGN OF THE AQUILA — One makes this gesture, typically used superstitiously, by crossing one's hands across the chest with thumbs interlocked, making a semblance of the Imperial Eagle.

TRANSCODING — A process by which psykers remove mindlock

VISTA-CASTER — Video communication unit
VISTA-PLATE — Viewscreen
VOID-DOCK — This is an internal docking bay, shielded and kept pressurized by a void-field.
VOID-FIELD — A smaller, less powerful version of the titan- or starship-based energy shields of similar name
VOID-HATCHES — These are large-scale bay doors, such as those used for small craft hangars on starships.
VOID-SHIELD — This is the energy field used as protection on large starships and titans. They collapse when overloaded, sometimes burning out the generators themselves, but otherwise they can be re-raised after resetting their systems.
VOX — This is the common name for a wide variety of radio-band communications devices.
VOX-CASTER — A radio transmitter
VOXMAT — A facility devoted to vox transmissions
VOX-SCREEN — A field that blocks vox transmissions
VOX-THIEVES — These devices are high-tech bugs that can capture both simple sound and vox transmissions in their vicinity
VOX-VISTA — A communication device that transmits both audio and video signals.

WARP ENGINE — These machines allow starships to breach the wall between reality and the Warp where they can ride the tides and currents of the immaterium, essentially moving far faster then light.
WAYSTATION — These compounds serve as rest stops and safe havens for Navis Nobilite navigators. They can be found in major systems or those at the nexus of trade routes.

XENOS MALEFICORUM, DE — This tome of the Inquisitorial Ordo Xenos describes the tactics of various alien races.