boil down vs diminish

boil down and diminish both are verbs.

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

As verbs, diminish is a hypernym of boil down; that is, diminish is a word with a broader meaning than boil down:

Other hypernyms of boil down include decrease, fall, lessen.

boil down (verb)	diminish (verb)
cook until very little liquid is left	decrease in size, extent, or range
be cooked until very little liquid is left	lessen the authority, dignity, or reputation of
be the essential element