If you go out to buy a waterproof phone, radio, or any other item, you're going to run into two kinds of salesmen. One will say, "sure it's waterproof". The other will say something like "It's rated to IPX67", or "it can be submerged in a puddle or a few feet of water for half an hour". Avoid the first salesman.
Industrially, people are very reluctant to say waterproof because they want a definition to test their products to. For example, consider the term waterproof camera. It means something different to someone going out on a boat and wants to make sure their phone's camera will work if it gets hit by water drops than it does to someone who wants to go SCUBA diving in 60 feet of water.
The manufacturing world has largely gone over to IP codes: the International Protection Marking, IEC standard 60529, sometimes interpreted as Ingress Protection Marking. On a product, the codes are denoted by the letters IP and two digits. The first denotes being sealed against solids or particles, and the second denotes being sealed against liquids. The first digit can run from 0 to 6 and literally runs from entry of something larger than a hand down to dust particles:
The second digit can run from 0 to 9 with a special suffix:
Level sized Effective against Description 0 — No protection against contact and ingress of objects 1 >50 mm Any large surface of the body, such as the back of a hand, but no protection against deliberate contact with a body part 2 >12.5 mm Fingers or similar objects 3 >2.5 mm Tools, thick wires, etc. 4 >1 mm Most wires, slender screws, large ants etc. 5 Dust protected Ingress of dust is not entirely prevented, but it must not enter in sufficient quantity to interfere with the satisfactory operation of the equipment. 6 Dust tight No ingress of dust; complete protection against contact (dust tight). A vacuum must be applied. Test duration of up to 8 hours based on air flow.
As you can see it's rather specific in what it says the product is protected against, and there's an additional column that I omitted which talks about how these things are tested!
Level Protection against Effective against 0 None — 1 Dripping water Dripping water (vertically falling drops) shall have no harmful effect on the specimen when mounted in an upright position onto a turntable and rotated at 1 RPM. 2 Dripping water when tilted at 15° Vertically dripping water shall have no harmful effect when the enclosure is tilted at an angle of 15° from its normal position. A total of four positions are tested within two axes. 3 Spraying water Water falling as a spray at any angle up to 60° from the vertical shall have no harmful effect, utilizing either: a) an oscillating fixture, or b) A spray nozzle with a counterbalanced shield.Test a) is conducted for 5 minutes, then repeated with the specimen rotated horizontally by 90° for the second 5-minute test. Test b) is conducted (with shield in place) for 5 minutes minimum. 4 Splashing of water Water splashing against the enclosure from any direction shall have no harmful effect, utilizing either: a) an oscillating fixture, or b) A spray nozzle with no shield.Test a) is conducted for 10 minutes. Test b) is conducted (without shield) for 5 minutes minimum. 5 Water jets Water projected by a nozzle (6.3 mm) against enclosure from any direction shall have no harmful effects. 6 Powerful water jets Water projected in powerful jets (12.5 mm nozzle) against the enclosure from any direction shall have no harmful effects. 6K Powerful water jets with increased pressure Water projected in powerful jets (6.3 mm nozzle) against the enclosure from any direction, under elevated pressure, shall have no harmful effects. Found in DIN 40050, and not IEC 60529. 7 Immersion, up to 1 m depth Ingress of water in harmful quantity shall not be possible when the enclosure is immersed in water under defined conditions of pressure and time (up to 1 m of submersion). 8 Immersion, 1 m or more depth The equipment is suitable for continuous immersion in water under conditions which shall be specified by the manufacturer. However, with certain types of equipment, it can mean that water can enter but only in such a manner that it produces no harmful effects. The test depth and/or duration is expected to be greater than the requirements for IPx7, and other environmental effects may be added, such as temperature cycling before immersion. 9K Powerful high temperature water jets Protected against close-range high pressure, high temperature spray downs.Smaller specimens rotate slowly on a turntable, from 4 specific angles. Larger specimens are mounted upright, no turntable required, and are tested freehand for at least 3 minutes at distance of 0.15–0.2 m.There are specific requirements for the nozzle used for the testing.This test is identified as IPx9 in IEC 60529.
As I alluded to above, many VHF radios are rated to IP67, sometimes called IPX7. There's no rating for dust because it's assumed that anything sealed against water is going to be sealed against dust and particles as well. I've seen ads for smartphones that imply a certain level of waterproofness, the commercial showed them being washed in soap and water, but no IP ratings on them.
A practical application of this subject that's important to me right now is waterproof stepper motors. Mine aren't. In my last couple of years at work, I got involved with evaluation and testing of stepper motors (the radar antennas were moved by stepper motors) which were rated to be extremely resistant to water spray and corrosion. For this to work, the motors had to designed to meet tough specifications from the start. It wasn't possible to take a standard part and just dip it some sort of coating. The motors were rated to MIL-STD-202G, a salt spray test with varying test times. Their motors looked better at 10 days than the competition at 2 days and survived all of our tests without missing a step.
To complicate things, there are other standards, like the older NEMA (National Electronics Manufacturing Association) ratings. NEMA 6 looks like it would be a worthwhile level to try for, if a NEMA rating is all you have.