waterproof

American  

[waw-ter-proof, wot-er-] / ˈwɔ tərˌpruf, ˈwɒt ər- /

adjective

1. impervious to water.

2. rendered impervious to water by some special process, as coating or treating with rubber.

   a waterproof hat.

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noun

waterproofs plural

1. Chiefly British. a raincoat or other outer coat impervious to water.

2. any of several coated or rubberized fabrics that are impervious to water.

verb (used with object)

waterproofs, present (3rd person singular) waterproofed, past participle, past waterproofing present participle

1. to make waterproof.

waterproof British  

/ ˈwɔːtəˌpruːf /

adjective

1. not penetrable by water Compare water-repellent water-resistant

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noun

1. a waterproof garment, esp a raincoat

verb

1. to make (a fabric, item of clothing, etc) waterproof

Usage

What does waterproof mean? If something is waterproof, water can’t soak it or get inside of it. For example, waterproof boots will keep your feet dry even if you walk in water. Waterproof is also commonly used as a verb meaning to make something waterproof, as in We need to waterproof this basement so it won’t flood during rainstorms. Waterproof is sometimes used in the U. K. as a noun to refer to a waterproof garment, especially a raincoat, as in It’s raining, so you’d better wear your waterproof. Example: Make sure you get a waterproof tent—the ones that are only water-resistant can still let the rain in.

Other Word Forms

Derived Forms

• waterproofer
  noun
• waterproofness
  noun

Inflected Forms

Nouns

• waterproofs
  plural

Participles

• waterproofing
  present
• waterproofed
  past

Conjugated Forms

Present

• waterproof
  simple
• waterproofs
  simple
• have waterproofed
  perfect
• has waterproofed
  perfect
• am waterproofing
  progressive
• are waterproofing
  progressive
• is waterproofing
  progressive
• have been waterproofing
  perfect progressive
• has been waterproofing
  perfect progressive

Past

• waterproofed
  simple
• had waterproofed
  perfect
• was waterproofing
  progressive
• were waterproofing
  progressive
• had been waterproofing
  perfect progressive

Future

• will waterproof
  simple
• will have waterproofed
  perfect
• will be waterproofing
  progressive
• will have been waterproofing
  perfect progressive

Etymology

Origin of waterproof

First recorded in 1730–40; water + -proof

Explanation

Water can't penetrate something that's waterproof. Umbrellas and rain boots don't work very well if they're not waterproof. Waterproof jackets will keep you dry even if it starts to rain, and waterproof mascara won't run in black streaks down your face even if you're weeping at a sad movie. You can use this word as a verb, too: "We should waterproof the tent before we go camping this weekend — it's supposed to pour!" If you're British, you might also use waterproof as a noun, to mean a waterproof rain coat.

Example Sentences

He has also designed boats, paddles and other waterproof products, and said he was curious about what materials had been used to paint the pool.

From BBC • Jun. 21, 2026

She invented a reusable, waterproof diaper cover made first from a shower curtain and later from nylon parachute cloth, into which mothers could insert a cloth diaper pad.

From The Wall Street Journal • Apr. 9, 2026

Bees, however, often coat their nests with a waxy secretion that creates a waterproof, polished interior.

From Science Daily • Apr. 3, 2026

Elon Musk tweeted in 2022 that the Cybertruck “will be waterproof enough to serve briefly as a boat.”

From Los Angeles Times • Mar. 19, 2026

Reaching into the waterproof bag, she pulled out a food packet at random.

From "Uglies" by Scott Westerfeld

Related Words

• rainproof