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speed

1 speed /ˈspiːd/ noun
plural speeds
1 speed
/ˈspiːd/
noun
plural speeds
Britannica Dictionary definition of SPEED
: the rate at which someone or something moves or travels
[noncount]
[count]
: the rate at which something happens or is done
[noncount]
[count]
[noncount] : the quality of being quick
[count] photography
: a measurement that indicates how quickly film reacts to light and that is expressed as a number (such as 100 or 200)
: the time during which a camera's shutter is open
[count] : a gear in a vehicle or bicycle
[noncount] informal : an illegal drug that makes a person feel more excited and full of energy

at speed

chiefly British
: very quickly : at a fast speed

full speed ahead

see 1full

up to speed

: having the latest information about something
: having the knowledge that is needed to do or understand something
2 speed /ˈspiːd/ verb
speeds; sped /ˈspɛd/ or speeded; speeding
2 speed
/ˈspiːd/
verb
speeds; sped /ˈspɛd/ or speeded; speeding
Britannica Dictionary definition of SPEED
always followed by an adverb or preposition, [no object] : to move fast
always followed by an adverb or preposition, [+ object] : to move (someone or something) somewhere very quickly
[no object] : to drive faster than the legal speed limit
[+ object] somewhat formal : to cause (an action, movement, process, etc.) to happen faster

speed up

[phrasal verb]
speed up or speed up (something or someone) or speed (something or someone) up
: to become faster or to make (something or someone) faster
see also speedup