moist
Slightly wet in a comfortable or helpful way.
Moist means slightly wet, usually in a way that's good or useful. A perfectly baked chocolate cake should be moist inside, not dry and crumbly. Gardeners want the soil around their plants to stay moist so roots can absorb water. When you wash your hands, they're wet, but after you dry them lightly, they might still be moist to the touch.
The word describes an in-between state: wet enough to be useful but not soaking. A moist towel has enough water in it to wipe down a counter. A moist sponge is ready to use for cleaning.
Whether moist is a good thing or a bad thing depends on what's moist. Brownies? Good. Your socks? Terrible!
You might hear someone say the air feels moist on a humid summer day, meaning there's a lot of water vapor floating around. Moisture is the noun form, referring to small amounts of water present in something.