concentrate vs boil down

concentrate is a noun but boil down is not a noun.

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

As verbs, concentrate and boil down are synonyms defined as:

Other synonyms of concentrate include reduce.

As verbs, concentrate and boil down are synonyms defined as:

Other synonyms of concentrate include decoct, reduce.

concentrate (noun)	boil down (noun)
a concentrated example of something
a concentrated form of a foodstuff; the bulk is reduced by removing water
the desired mineral that is left after impurities have been removed from mined ore

concentrate (verb)	boil down (verb)
cook until very little liquid is left	cook until very little liquid is left
make denser, stronger, or purer	be cooked until very little liquid is left
make central	be the essential element
be cooked until very little liquid is left
make more concise
compress or concentrate
direct one's attention on something
draw together or meet in one common center