boil down phrasal verb ( see also ↑ boil )
1 . boil down to something informal if a long statement, argument etc boils down to a single statement, that statement is the main point or cause:
It boils down to a question of priorities.
2 . boil something ↔ down to make a list or piece of writing shorter by not including anything that is not necessary:
You can boil this down so that there are just two main categories.
3 . if a food or liquid boils down, or if you boil it down, it becomes less after it is cooked:
Spinach tends to boil down a lot.
boil something ↔ down
glue made from boiling down old sheepskins