This is the 11937th most frequent Spanish word.
impermeable
Waterproof.
Here, 'impermeable' is used as a noun to refer to a raincoat.
El impermeable que compré es muy cómodo.
The raincoat I bought is very comfortable.
In this case, 'impermeable' is used as an adjective to describe something waterproof.
Mi chaqueta es impermeable.
My jacket is waterproof.
Here, 'impermeable' is an adjective that characterizes the material as resistant to water.