For the education of those new to the lifestyle...
I myself learned these terms and probably a few more from a mixture of the Warriors video game and Marc Ecko's Getting Up game.
ALL CITY: (adj.) When a writer's name is up all over the city and major subway lines. This is every writer's ambition.
BACKGROUND: (n.) The colour or design painted behind the piece to make it stand out from the wall or train. Backgrounds are also used to make a graffiti stand out from all the tags and assorted scribbling on a subway car that make the piece hard to discern.
BENCH: (n.) Subway station where writers congregate and watch trains.
(v.) The act of watching trains.
BLOCKBUSTER: (n.) A piece with big square letters and usually in two colours.
BOMB: (v.) Prolific painting.
BUBBLE LETTERS: (n.) A type of graffiti letters with rounded shapes. Often used for throw-ups, as they allow quick formation.
BUFF: (v.) To erase.
BURNER: (n.) A technically and stylistically well executed piece, generally done in bright colours.
CHARACTER: (n.) A cartoon figure, TV or popular culture character painted to add humour or emphasis to a piece. In some pieces, the character takes the place of a letter in the word.
CREW: (n.) Loosely organised group of writers who also tag the crew initials along with their name. Crew names are usually three letters.
END TO END: (n.) A piece painted from one end of a train to the opposite end.
FLOATERS: (n.) A throw-up done on subway car panels at window level.
GET UP: (v.) When the proliferation of a writer's name has led to high visibility.
INSIDES: (n.) Subway car interiors.
OUTLINE: (n.) The framework of a piece. After fill-in and designs have been applied, the outline is re-executed to define the letters.
PANEL PIECE: (n.) A painting below the windows and between the doors of a subway car.
PIECE: (n.) A writer's painting, short for masterpiece.
PIECE BOOK or BLACK BOOK: (n.) A writer's sketch book. Used for personal art development and or the collection of other artists' work.
PRODUCTION: (n.) Large scale murals with detailed pieces and illustrations. Often two or more writers collaborate to do a production.
ROLL CALL: (n.) Tagging everyone's name in a crew, or the list of people who helped create it to the side of the piece. Not done very often.
ROLLER LETTERS: (n.) Names rendered with bucket paint and rollers.
SCRUB: (n.) A certain type of throw-up (usually two colours) that is filled in very quickly with back-and-forth lines, rather than filled in solid.
SIDEBUSTING: (v.) To paint your name right next to somebody whose art was there first.
SILVER: (n.) A piece or throw-up with only silver for a fill in.
TAG: (n.) A writer's signature with marker or spray paint.
TAGGER: (n.) As opposed to writer; this term is usually used to refer to those who only do tags and throw-ups and who never paint pieces
THROW-UP: (n.) A name painted quickly with one layer of spray paint and an outline. Throw-ups are either bubble letters or very simple pieces using only two colours.
TOP-TO-BOTTOM: (n.) A piece which extends from the top of the car to the bottom.
TOY: (n.) Inexperienced or incompetent writer.
THREE-D: (n.) A three-dimensional style of letters, used for added effect on basic letters, sometimes applied to wildstyle for an extra level of complexity.
WILDSTYLE: (n.) A complicated construction of interlocking letters. It is a very difficult style that consists of arrows and connections. Wildstyle is considered one of the hardest styles to master and pieces done in wildstyle are often difficult to read and understand for non-writers.
WINDOW-DOWN: (n.) A piece done below the windows of a subway car.
WHOLE CAR: (n.) A piece covering the whole subway car, from end to end and from top to bottom.
WHOLE TRAIN: (n.) Pieces covering the whole train.
WRITER: (n.) Practitioner of the art of graffiti.