Sigilian Cant

Sigilian cant, or 'the cant' as it is called in Sigil, is a form of slang used extensively in the City of Doors. Normally it is associated with the poor and the lower classes where it is used quite heavily, but many of these words are in use amoung the well off and the upper classes. The cant is most prominent in Sigil, and anyone who spends any time there becomes familiar with it, but it is also common in the Outlands and in the various gate towns, especially those that abut the lower planes.
Use of the cant outside of Sigil or the Outlands is rare but not unheard of, and those of the lower planes especially make some use of it. It has become the defacto slang of the common trade tongue spoken throughout the planes; usually called planar common it is not altogether different from the common tongue spoken in Toril, and those who can speak one form of common can largely understand speakers of the other.

This is a glossary of common cant words and phrases. Note that new slang is being invented all the time, and some slang falls out of common use from generation to generation, but this list is representative of the modern cant.
It is not an exhaustive list and will be updated whenever characters encounter new phrases, especially the slang names for Factions and Sigil-only cant that is not used anywhere else.

Bar that: an almost, but not quite, polite way of saying "shut up" or "don't talk about that".

Barmy: Insane, typically those who have been "touched" by the impossible hugeness of the planes and have not returned to their minds.

Basher: A neutral reference to a person, usually (but not always) a thug or fighter.

Berk: A fool, especially one who got himself into a mess when he should have known better.

Birdcage: A cell, prison, or the like.

Blinds: Anything impossible or hopeless. To "hit the blinds" is to find ones self in a difficult situation.

Blood: An expert, a sage, or a professional in any field. A champion gladiator can be a blood, as can a practiced sorcerer. Calling someone a blood (and meaning it) is a mark of high respect.

Bone-Box: Your mouth. "Stop rattlin' yer bone-box" means to shut up, especially to a braggart or someone making a threat.

Brain-Box: Your head, often crude or uncomplimentary. "Go soak yer brain-box" is a common idiom. "He banged his fool brain-box on it" means a berk finally figured something obvious out.

Bub: Booze, usually wine or ale but always cheap and barely drinkable.

Bubber: A drunk, especially if he, she or it has fallen on hard times. Bubbers get, and expect, no sympathy from anyone.

Burg: Any town smaller than Sigil, in size or spirit. That doesn't leave too many places that aren't burgs.

Cager: A native or resident of Sigil.

Canny: Smart or talented.

Case: The house or place where a cutter lives. Has a positive connotation as a nice or decent place.

Chant, The: An expression that means news, local gossip, the facts, the moods or anything else about what's happening. "What's the chant" is a way of asking for the latest news a basher's heard.

Clueless, The: The folks who just don't get it, usually primes.Use this on a planar and there'll likely be a fight. Also an adjective, like calling someone a "clueless berk",

Cross-trade: The business of thieving, or anything else illegal or shady.

Cutter: A complimentary term that refers to anybody, male or female. It suggests a certain amount of resourcefulness or daring and is a lot better than calling someone a berk.

Dark: Anything secret is said to be dark. "Here's the dark of it" is a way of saying "this is the secret truth of the matter".

Dead-book: A body in the dead-book is dead. To "write someone into the dead-book" means to kill them.

Faction: One of the 15 philosophical groups that run Sigil.

Garnish: A bribe.

Gate: Another term for a portal. All gates in Sigil are generally referred to as portals. Also used to describe any sort of passageway or conduit between one plane and another. There was once a distinction between portal, which requires a portal key, and a gate, which does not, but it is rarely honoured anymore with portal being the catch-all word.

Gate-Town: a burg on the Outlands that has a Gate to another plane. Each plane has one gate-town, and the town often has the same basic appearance, outlook and attributes as the inhabitants, architecture and terrain of the corresponding plane.

High-Up: Powerful. This refers to a spell, position, or anything else that can be measured. Also a person of money and influence. It is considered bad form to label yourself as a high-up, it is a term others bestow.

Jink: Money and/or coins.

Kip: Any place a cutter can put his feet up and sleep for a night, especially a low brow or cheap establishment. To "call kip" is to make a place your home, at least for a while.

Knight of the Cross-Trade: Also, Knight of the Post - a thief, cheat and a liar.

Lann: To tell or inform.

Leafless Tree, The: The gallows.

Leatherhead: An idiot; dull or thick witted.

Lost: Dead, as in "not coming back without a resurrection spell".

Mark: To make note of something, or "to be marked" as in to be identified or labelled, especially in regards to an allegiance ("That berk was marked as a Tanar'ri").

Peel: A swindle, con or trick, often used as a verb, as in "to pull a peel" or to "peel some berk".

Peery: Suspicious and on one's guard.

Petitioner: A mortal who has died and reformed on the plane of his alignment and/or deity without memory of his former life. A petitioner's ultimate goal is to become one with the plane he's occupying, although no one (not even the petitioner) quite knows the dark of this.

Pike it: A useful all purpose rude phrase akin to "stick it".

Planar: Any being native to a plane other than the Prime Material Plane. These are living beings, not petitioners.

Plane-Touched: A planar cross-breed. Any offspring of a planar native and a human. Tieflings are plane touched as are aasimar and genasi. Cambions and other half-breed fiends are also considered plane touched.

Planewalker: A cutter who travels the planes looking for adventure, jink or glory - basically a planes travelling adventurer. Usually, to refer to someone as a planewalker carries a tone of some respect, for such individuals are considered capable, knowledgeable and experienced.

Power: A being of incredible might, drawing energy from those who worship it and able to grant spells to Priests. Also called a deity or god.

Prime: The Prime Material Plane or someone from that plane. Also a single prime material world (such as Faerun).

Proxy: A mighty servant of a Power, usually a former mortal worshipper of that power.

Scragged: Arrested or caught.

Screed: Lies, tall tales and similar verbal flights of fancy.

Sod: An unfortunate or poor soul. Use it to show sympathy for an unlucky cutter or sarcastically for those who get into their own messes (like a berk). Also used generally as a catch all swear word ("Sod it", "Sod off", "Ya soddin' berk", "Ya stupid sod", "Sod off ya soddin' sod", etc).

Sodding: A derogatory word used to stress magnitude. A "sodding idiot" is an amazingly stupid berk.

Spellslinger: A wizard.

Tumble to: To understand, figure out, or find something out. "He tumbled to the dark of it."

Turn Stag: To betray somebody or use treachery.

Well-Lanned: Connected, in-touch or otherwise blessed numerous friends, allies and informants.

Wig-Wag: To chat or talk.