plural speeds
1
: the rate at which someone or something moves or travels
The trucks gain/gather speed as they drive down the hill. = The trucks pick up speed as they drive down the hill. [=the trucks go faster as they drive down the hill]
This instrument measures wind speed.
He was running at full/top speed. [=as fast as possible]
The machine was operating at high/medium/low speed.
traveling at nearly the speed of light/sound
Under the right conditions the car can reach speeds over 200 miles an hour.
The vehicle maintained a speed of 40 miles per hour.
2
: the rate at which something happens or is done
The work was done with remarkable speed.
They ate their lunch at lightning speed. [=extremely quickly]
This computer works at a much faster processing speed than my old one.
He types at a speed of about 50 words per minute. = His typing speed is about 50 words per minute.
3
: the quality of being quick
The machine chops up tree branches and leaves with speed and ease.
4
photography
a
: a measurement that indicates how quickly film reacts to light and that is expressed as a number (such as 100 or 200)
200 speed film
b
: the time during which a camera's shutter is open
faster/slower shutter speeds
5
: a gear in a vehicle or bicycle
a three-speed bicycle
Her old car has four speeds.
6
informal
: an illegal drug that makes a person feel more excited and full of energy
He was high on speed.
speeds; sped
ˈspɛd 
or speeded; speeding
or speeded; speeding
1
always followed by an adverb or preposition
: to move fast
A group of kids sped past us on their bikes.
They jumped in the car and sped/speeded away.
A car was speeding down/up the street.
2
always followed by an adverb or preposition
: to move (someone or something) somewhere very quickly
An ambulance sped her to the hospital.
3
: to drive faster than the legal speed limit
I got pulled over twice last month because I was speeding on the highway.
Don't speed.
4
somewhat formal
: to cause (an action, movement, process, etc.) to happen faster
We kept the plants under artificial lights at night to speed their growth.
Is there anything we can do to speed the process (along)?
Cite this Entry
“Speed.” Merriam-Webster.com Simple Definition, Merriam-Webster, https://www.merriam-webster.com/simple/speed. Accessed 22 Jun. 2026.
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