If someone is happy, I can refer to that state as that person's happiness.

If a watch is waterproof, do I refer to the watch's waterproofness, waterproofity, or what?

TFD has an entry that fits for happy, but not for waterproof.

I realize resistance is related ("I have a water resistant watch."), but I am curious if there is a word based on waterproof specifically.

In other words, is there a noun form of the adjective waterproof?

  • 1
    Interesting. "Impermeability" has little to do with the words water and proof!
    – JAM
    Aug 16, 2012 at 20:42
  • 1
    Waterproofness: "the property of being waterproof".
    – RegDwigнt
    Aug 16, 2012 at 21:19
  • @RegDwightАΑA I've never used, nor do I believe I've ever heard that usage before today...
    – Gaffi
    Aug 16, 2012 at 21:21
  • It seems that when manufacturers need to measure waterproofness they use they phrase "waterproof rating" instead of "waterproofness".
    – JLG
    Aug 16, 2012 at 21:26
  • 2
    FWIW, "waterproofness" gets 34 instances in COCA. corpus.byu.edu/coca/?c=coca&q=17675710
    – nohat
    Aug 17, 2012 at 4:48

3 Answers 3


Waterproofness as a noun does indeed exist.

  • 1
    That sounds so wrong to me, but it looks like that's it. Thanks!
    – Gaffi
    Aug 16, 2012 at 20:58

Despite a comment to the contrary, impermeable has a sense meaning waterproof: “not allowing passage, especially of liquids; waterproof”. Also consider hydrophobic, in its sense “lacking an affinity for water; unable to absorb, or be wetted by water”; and at a bit more of a stretch, insoluble.

For a noun sort of word, besides previously-mentioned waterproofness consider hermeticity, "the condition of being hermetic (airtight)". While hermetic refers to air-tightness or gas-tightness, it is sometimes used to describe diving chambers, which are both air-tight and water-tight, and also is used to describe underwater assemblies. For a watch, either of hermetically sealed or water-tight might do.

  • I can certainly see uses of impermeable dealing with non-aquatic situations. However, I can't quickly come up with the same context for using waterproof. (The army's defense was impermeable.)
    – Gaffi
    Aug 16, 2012 at 20:57

As others have said, waterproofness does exist. The OED lists a 1943 citation:

They offer advantages over certain other cellulose thermo-plastic adhesives by reason of their great toughness, waterproofness and heat sealing properties.

along with another quote from the late 1970s that also references research from that same era:

The old style boot greases were developed during World War II for government use. Waterproofness of combat boots was the main objective.

Interestingly enough, even though the OED had an entry for waterproofness, there was no entry for soundproofness, fireproofness, or bulletproofness. That means, I suppose, I can talk about the waterproofness of my watch, but I'll need to find some other way to describe the the fireproofness of my pajamas, the soundproofness of my recording studio, and the bulletproofness of my limosine's windows. Weatherproofness, on the other hand, is listed as a word.

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