ENGLISH
REFERENCE

waterproof

adj. · v. · n.
US //ˈwɔtɝˌpɹuf// UK //wˈɔːtəpɹˌuːf// wa·ter·proof
  1. 1 impervious to water (adj.)
    B1 Intermediate

    made of a material that does not let water pass through it.

    impervious to water; specifically describing materials or objects designed to prevent the penetration of liquid water.

    Example

    You should wear a waterproof jacket because the weather report predicts heavy rain.

    Example

    The new smartphone model is rated as fully waterproof, allowing it to be submerged in shallow water for up to thirty minutes without damage.

    Usage

    Often used to describe clothing, electronics, or building materials.
  2. 2 incapable of failing (adj.)
    C2 Proficiency Literary

    something that is so well-planned or strong that it cannot fail or be attacked.

    metaphorically unassailable or incapable of being defeated or found false.

    Example

    The lawyer presented a waterproof argument that the jury couldn't disagree with.

    Example

    The prosecution spent months constructing a waterproof case, ensuring that every piece of forensic evidence was corroborated by multiple witnesses.
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  1. 3 to make water-resistant (v.)
    B2 Upper Intermediate

    to treat something with a special substance so that water cannot get in.

    to treat a surface or object with a substance to render it impervious to water. Transitive use requiring a direct object.

    Example

    I need to waterproof my hiking boots before we go on the camping trip.

    Example

    The contractor recommended that we waterproof the basement walls to prevent moisture from seeping through the foundation during the spring thaw.
  2. 4 a rain coat (n.)
    B2 Upper Intermediate British English

    a coat or piece of clothing made from material that keeps you dry.

    a garment, such as a raincoat or mackintosh, made from water-resistant material.

    Example

    Don't forget to pack your waterproof if you are going walking in the mountains.

    Example

    He pulled his yellow waterproof tight against the gale, though the salt spray still found its way past his collar.
Origin

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

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