This seemed a little sus to me so I checked the dictionary. Merriam-Webster says wet can mean consisting of liquid such as water. (See 1a of screen capture).

Wet is used as a synonym for rain in my local dialect. The endless flexibility of english is amazing. Noun that verb! Adjectivize all the words!

Just don’t put colour before size in your stack of adjectives or everyone cringes, for some reason.

One of the things water makes wet is water.

Water touches water, therefore water is wet

Water is wet because it's multiple molecules making each other wet. So a single water molecule is dry.