adjective.
Proof against penetration or permeation by water; impervious to water.
noun.
A substance or preparation for rendering cloth, leather, etc., impervious to water.
noun.
Cloth made waterproof, or any article made of such cloth, or of other waterproof material, as rubber; esp., an outer garment made of such material.
transitive verb.
To render impervious to water, as cloth, leather, etc.