The state of moving quickly or the capacity for rapid motion; rapidity. The rate of motion or action, specifically (mathematics)/(physics) the magnitude of the velocity; the rate distance is traversed in a given time. (photography) The sensitivity to light of film, plates or sensor. (photography) The duration of exposure, the time during which a camera shutter is open (shutter speed). (photography) The largest size of the lens opening at which a lens can be used. (photography) The ratio of the focal length to the diameter of a photographic objective. (slang, uncountable) Amphetamine or any amphetamine-based drug (especially methamphetamine) used as a stimulant, especially illegally. (archaic) Luck, success, prosperity. (slang) Personal preference. (finance, uncountable) A third-order measure of derivative price sensitivity, expressed as the rate of change of gamma with respect to changes in the underlying asset price. (intransitive, archaic) To succeed; to prosper, be lucky. (transitive, archaic) To help someone, to give them fortune; to aid or favour. (intransitive) To go fast. (intransitive) To exceed the speed limit. (transitive) To increase the rate at which something occurs. (intransitive, slang) To be under the influence of stimulant drugs, especially amphetamines. (obsolete) To be expedient. (archaic) To hurry to destruction; to put an end to; to ruin. (archaic) To wish success or good fortune to, in any undertaking, especially in setting out upon a journey. To cause to make haste; to dispatch with celerity; to drive at full speed; hence, to hasten; to hurry. To hasten to a conclusion; to expedite.