hasten vs buck

hasten is not a noun while buck is a noun.

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

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

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

hasten (noun)	buck (noun)
	mature male of various mammals (especially deer or antelope)
	a framework for holding wood that is being sawed
	a gymnastic horse without pommels and with one end elongated; used lengthwise for vaulting
	a piece of paper money worth one dollar

hasten (verb)	buck (verb)
act at high speed	jump vertically, with legs stiff and back arched
cause to occur rapidly	move quickly and violently
move hurridly	resist
speed up the progress of; facilitate	to strive with determination