(dated) playmate; companion for someone (especially children) to play with.
sweatproof
sweatproof
adj
Resistant to sweat.
wasteproof
wasteproof
adj
Designed to prevent wastage.
waterproof
waterproof
adj
(figurative) Incapable of failing; unassailable.
Made of or covered with material that doesn't allow water in.
Resistant to the effects of water.
noun
A substance or preparation for rendering cloth, leather, etc., impervious to water.
Cloth made waterproof, or any article made of such cloth, or of other waterproof material, as rubber; especially, an outer garment made of such material.