speed vs whizz

speed and whizz both are nouns.

Word	Noun	Adjective	Verb	Adverb
speed	Yes	No	Yes	No
whizz	Yes	No	Yes	No

As verbs, whizz is a hyponym of speed; that is, whizz is a word with a more specific, narrower meaning than speed:

Other hyponyms of speed include dart, fleet, flit, flutter, run, whizz along, zoom, zoom along.

speed (noun)	whizz (noun)
changing location rapidly	someone who is dazzlingly skilled in any field
a central nervous system stimulant that increases energy and decreases appetite; used to treat narcolepsy and some forms of depression
a rate (usually rapid) at which something happens
the ratio of the focal length to the diameter of a (camera) lens system
distance travelled per unit time

speed (verb)	whizz (verb)
move faster	move along very quickly
cause to move faster	make a soft swishing sound
move very fast
travel at an excessive or illegal velocity
move hurridly