(1):

(a.) Proof against penetration or permeation by water; impervious to water; as, a waterproof garment; a waterproof roof.

(2):

(v. t.) To render impervious to water, as cloth, leather, etc.

(3):

(n.) 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.

(4):

(n.) A substance or preparation for rendering cloth, leather, etc., impervious to water.