speed vs buck

speed and buck both are nouns.

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

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

Other hyponyms of speed include barge, push forward, thrust ahead, charge, shoot, shoot down, tear, dart, dash, flash, scoot, scud, shoot.

speed (noun)	buck (noun)
changing location rapidly	mature male of various mammals (especially deer or antelope)
a central nervous system stimulant that increases energy and decreases appetite; used to treat narcolepsy and some forms of depression	a framework for holding wood that is being sawed
a rate (usually rapid) at which something happens	a gymnastic horse without pommels and with one end elongated; used lengthwise for vaulting
the ratio of the focal length to the diameter of a (camera) lens system	a piece of paper money worth one dollar
distance travelled per unit time

speed (verb)	buck (verb)
move faster	jump vertically, with legs stiff and back arched
cause to move faster	move quickly and violently
move very fast	resist
travel at an excessive or illegal velocity	to strive with determination
move hurridly