speed

noun

• 1 [mass noun] the rate at which someone or something moves or operates or is able to move or operate:we turned on to the runway and began to gather speed an engine running at full speed [count noun]:the car has a top speed of 147 mph
• rapidity of movement or action:the accident was due to excessive speed
• the rate at which something happens or is done:they were bemused by the speed of events the course is delivered on CDROM so students can progress at their own speed

• 2each of the possible gear ratios of a bicycle.
• US or dated each of the possible gear ratios of a motor vehicle.

• 3the light-gathering power or f-number of a camera lens.
• the duration of a photographic exposure.
• the sensitivity of photographic film to light.

• 4 [mass noun] informal an amphetamine drug, especially methamphetamine.

• 5 [mass noun] archaic success; prosperity:wish me good speed

verb (past and past participle sped /spɛd/)

• 1 [no object, with adverbial of direction] move quickly:I got into the car and home we sped
• (past and past participle speeded) [no object] (of a motorist or vehicle) travel at a speed that is greater than the legal limit:the car that crashed was speeding
• (past and past participle speeded) (speed up) move or work more quickly:you force yourself to speed up because you don’t want to keep others waiting
• (past and past participle speeded) [with object] cause to move or happen more quickly:they sought to speed up decision-making

• 2 [with object] archaic make prosperous or successful:may God speed you

• 3 [no object] informal take or be under the influence of an amphetamine drug:more kids than ever are speeding, tripping, and getting stoned