moistness       
noun [ U ] uk/ˈmɔɪst.nəs/ us/ˈmɔɪst.nəs/
 润,湿润
the quality of being slightly wet, especially in a pleasant or good way
  Sauces add moistness, flavour, and interest to the dishes they accompany. 调味汁可以增加菜肴的湿度、风味和趣味。 
 Guy felt a growing dryness in his throat and a moistness in his palms. 盖伊感到喉咙越来越干,手掌越来越湿。 
 See: moist
 - More examples
- The cake lacked the moistness and fruitiness of the other cakes.
- December 28th gave us another overcast sky with little wind and a moistness in the air.
- Its natural moistness and deep, rich molasses flavor makes it ideal for full-flavored or savory recipes.