speed

noun

1.
distance travelled per unit time
velocity
Derived from:
speed speedy
2.
a rate (usually rapid) at which something happens
skeeth yareness fastness swiftness
Derived from:
speed speedy
3.
changing location rapidly
hurrying speeding
Derived from:
speed speedy
4.
the ratio of the focal length to the diameter of a (camera) lens system
f number focal ratio stop number
5.
a central nervous system stimulant that increases energy and decreases appetite; used to treat narcolepsy and some forms of depression
amphetamine pep pill upper