verb / noun
boil
BOYL/bɔɪl/
To bubble vigorously as liquid becomes vapor through heat.
The water boils in the open saucepan.

Etymology
Latin bullire focused on bubbling and seething, the visible movement of heated liquid. English boil first described that condition, then also came to mean causing a liquid to enter it.
In context
here we've got liquid water that's normally familiar with it being in a liquid state and when we boil it it turns into a gas