waterproof

Etymology

water + -proof. Compare West Frisian wetterproef (“waterproof”), Dutch waterproef (“waterproof”).

adj

1. Resistant to the effects of water.
2. Made of or covered with material that doesn't allow water in.
3. (figurative) Incapable of failing; unassailable.
   The only waterproof plan and the one increasingly adopted by leading trades is the consolidation of the interests of all parties in a scheme of amalgamation. 1931, The British Clay Worker
   Especially within an international framework, guarding this process is of the utmost importance. The eyes of the world are focussed on the action at hand and demand a waterproof plan and execution. 2001, W. A. M. van Dijk, J. L. Hovens, Netherlands. Koninklijke Marechaussee, Arresting war criminals
   Unless you have a 100 percent waterproof plan to defraud insurance companies, I would suggest you don't do it. 2013, Barry Davies, Soldier of Fortune Guide to How to Disappear and Never Be Found, Skyhorse Publishing, Inc.

verb

1. To make waterproof or water-resistant.
   The dawn of the oil age was fairly recent. Although the stuff was used to waterproof boats in the Middle East 6,000 years ago, extracting it in earnest began only in 1859 after an oil strike in Pennsylvania. The first barrels of crude fetched $18 (around $450 at today’s prices). 2013-08-03, “Yesterday’s fuel”, in The Economist, volume 408, number 8847

noun

1. A substance or preparation for rendering cloth, leather, etc., impervious to water.
2. 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.