DBM - Double-Breasted Mattress Thrasher - when you're out 'bird' watching.
Death Grip - Usually how a first time rider grabs the handle bars.
Denier - a unit of measurement used to describe the strength of a material like nylon. Simply - the bigger the number the bigger the thread.
Detonation - See Pre-Ignition
DILLIGAF - Do I Look Like I Give A F**K
Displacement - 1. The size of an engine, in cubic centimeters (cc) or cubic inches (ci). 2. The volume through which the piston travels during a single stroke of an engine. This term is sometimes also used for the total volume displaced by all engine pistons. The displacement is measured in cubic centimeters (ccm).
Donor Cycle - Firefighter Term for Sport bikes because their drivers tend to kill themselves.
Dos Equis - Honda CBR1100XX Blackbird
DOT - Department of Transportation
Drag Bars - A straight styled handlebar that does not sweep up from the risers. Low, flat, straight handlebars.
Drag Pipes - These were short exhaust pipes that ran low along the frame.
DSA - Driving Standards Agency. The UK government body which, among other things, controls the content of the British bike test.
DTGO - Dyin' To Get Off - Refers to either the rookie female passenger or the seasoned one, depending on how you look at it.
Dual Sport - A dual purpose motorcycle, made for both on and off the road travel.
Duals - 2 seperate Exhaust pipes, ie one each for front andrear cylinder.