speed vs flit

speed and flit both are nouns.

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

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

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

speed (noun)	flit (noun)
changing location rapidly	a sudden quick movement
a central nervous system stimulant that increases energy and decreases appetite; used to treat narcolepsy and some forms of depression	a secret move (to avoid paying debts)
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)	flit (verb)
move faster	move along rapidly and lightly; skim or dart
cause to move faster
move very fast
travel at an excessive or illegal velocity
move hurridly