speed vs whizz along

speed is a noun but whizz along is not a noun.

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

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

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

speed (noun)	whizz along (noun)
changing location rapidly
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 along (verb)
move faster	move along very quickly
cause to move faster
move very fast
travel at an excessive or illegal velocity
move hurridly