boil down

definition: to cook until very little liquid is left
example: I boiled down the sauce until it was thick.
speech part: verb
synonyms: concentrate
definition: to be cooked until very little liquid is left
example: I boiled down the stock until it was thick and creamy.
speech part: verb
synonyms: concentrate
definition: to be the essential element
example: Let's boil it down to the facts.
speech part: verb
synonyms: reduce

How boil down is being used?