Cage - In general, any motorized vehicle that isn't a motorcycle. Strictly speaking cages are cars, SUV's, pickup's and such. Big trucks are not really cages.
Clip-on - The handlebars on sportbikes. The left and right bars are separate parts and attach to the fork tubes. They can attach to the fork tube above or below the top piece of the triple clamp. This arrangement is quite different than the single tubular bar which is used on most other types mototcycles.
DVM - Digital Volt Meter. An instrument that measures DC and AC voltage and current as well as resistance. The word digital refers to the numeric LCD display on the instrument. DMM's vary a lot size, price, and accuracy.
DMM - DIgital Multi-Meter. See DVM above.
Fastex - The name of the manufacturer of a line of black nylon reinforced plastic buckles and other parts for securing nyon straps. You'll find Fastex buckles on most tank bag mounting straps, the closure buckle for dry bags, soft saddle bags, and other soft luggage. They are also used on a lot of back packs and other camping gear. You can buy Fastex buckles and other parts at most campung supply stores and also at Campmor. There is another manufacturer of a similar line of strap buckles called Kifco. They work as well as Fastex but they are not compatible. The opening on the female Fastex buckle is rectangular whereas the Kifco buckle is a bit oval (still nearly rectangular but with the narrow dimension rounded a bit) If you're buying extra buckles be sure that you're buying the same type as is used on your bag. The name of the buckle will be molded somewhere on the buckle, usually on the female part.
LCD - Liquid Crystal Diode. A electronic display capable of displaying alphanumeric as well as graphical information. The display characters are usually a very dark green, almost black, and the background is a very pale green-gray.
OEM - Original Equipment Manufacturer. This term is usually used when refering to the manufacturer of replacement parts or accessories. The OEM would be Honda or Yamaha as opposed to Lockhart-Philips or Givi.
Sissy Bar - A vertical piece, usually made of steel, located at the back of the seat and attached to the rear sub-frame. Sissy bars are primarily cosmetic but can be used as a back rest or as a place to attach luggage. Sissy bars were fairly common on chopper style bikes of the late sixties and seventies. A less gaudy, but no less silly looking, version of the sissy bar is starting to make a comeback with the resurgence of the cruiser stype bikes.