When describing something as wet, you generally men there is water stuck to the surface. In other words, the water needs to have some force binding it to the wet object; a hydrophobic item can have water sitting on it but may not be considered 'wet' as the water is not attached and will fall off with no resistance. We know that the 'sticky' nature of water is a magnetic force caused by the polar nature of H2O molecules interacting with other molecules. Based on this, we can say that when water interacts with surface molecules of another object in a way that causes sticking, that object is wet.
The polarity of water molecules causes them to interact with each other, giving water it's physical properties. Through hydrogen bonding, the molecules attract each other with relatively strong forces, causing them to stick to each other. If you were to take any cross-sectional plane in a body of water and treat it as a surface, the molecules along that plane would not simply be next to water molecules, but stuck to other water molecules. This means that you can consider this surface to have water stuck to it, making it wet.
Because this continues through the whole volume of water, all of the water in a body of liquid-state can be considered to have water stuck to it. Because of this, water is wet.
