moistness

noun2

1. •
   The property of being moist.
2. •
   (no longer used) That which moistens or makes damp or wet; exuding fluid; liquid in small quantity.

   • The moistnesse which the roote of a tree suckes becomes a trunke, a leafe, and fruite: And the aire being but one, applied unto a trumpet, becommoth diverse in a thousand sorts of sounds. — 1603