Moisture is the feeling of wetness — what you want in your cupcake but not in your diapers.
Moisture is the noun related to the adjective moist, which you might use to describe damp soil, clammy air, or melt-in-your-mouth desserts. Moisture has also been known to promote mold growth and frizz otherwise tame hair, so it doesn't have many fans — other than tropical plants and the very thirsty.
