waterproof

adj

1. Resistant to the effects of water.
2. Made of or covered with material that doesn't allow water in.

   “The captain did a safety drill. This covered where the emergency position-indicating radio beacon (EPIRB) was located, how to make a mayday call, and where the fire extinguishers were. A crew member demonstrated how to put on an immersion suit. These survival suits are waterproof full-body garments with a hood and integral three-finger gloves and boots. They are bulky and hard to get on but far more likely to save your life in cold water than a lifejacket.”

3. (figuratively)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.”

   “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.”

   “Unless you have a 100 percent waterproof plan to defraud insurance companies, I would suggest you don't do it.”

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).”

noun

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

   “Carrados dropped the near window as a man in glistening waterproof stepped from the shelter of a lich-gate and approached.”