boil down vs preparation

boil down is not a noun while preparation is a noun.

Word	Noun	Adjective	Verb	Adverb
boil down	No	No	Yes	No
preparation	Yes	No	No	No

boil down (noun)	preparation (noun)
	activity leading to skilled behavior
	preparatory school work done outside school (especially at home)
	the activity of putting or setting in order in advance of some act or purpose
	the act of preparing something (as food) by the application of heat
	the cognitive process of thinking about what you will do in the event of something happening
	(music) a note that produces a dissonant chord is first heard in a consonant chord
	the state of having been made ready or prepared for use or action (especially military action)
	a substance prepared according to a formula

boil down (verb)	preparation (verb)
cook until very little liquid is left
be cooked until very little liquid is left
be the essential element