Waterproof, impervious to water; (often) spec. made waterproof by the application of an agent or substance. Also: provided with, or wearing…

Of a fabric or garment: made showerproof by the application of an agent or substance.

Made of pegamoid. Also figurative: impassive, impervious, not susceptible to emotion.

A proprietary name for: a breathable waterproof material used chiefly for outdoor clothing. Frequently attributive.