put to work vs rack

put to work is not a noun while rack is a noun.

Word	Noun	Adjective	Verb	Adverb
put to work	No	No	Yes	No
rack	Yes	No	Yes	No

As verbs, rack is a hyponym of put to work; that is, rack is a word with a more specific, narrower meaning than put to work:

Other hyponyms of put to work include exercise, work, work out, computerise, computerize, cybernate, exploit, overwork.

put to work (noun)	rack (noun)
	a rapid gait of a horse in which each foot strikes the ground separately
	a form of torture in which pain is inflicted by stretching the body
	a support for displaying ot holding various articles
	an instrument of torture that stretches or disjoints or mutilates victims
	the destruction or collapse of something
	rib section of a forequarter of veal or pork or especially lamb or mutton

put to work (verb)	rack (verb)
cause to work	torture on the rack
	seize together, as of parallel ropes of a tackle in order to prevent running through the block
	place in a rack
	work on a rack
	stretch to the limits
	torment emotionally or mentally
	go at a rack
	draw off from the lees
	run before a gale
	fly in high wind
	obtain by coercion or intimidation
	put on a rack and pinion