1. The act of making something slightly wet
   "The chef's moistening of the ingredients helped them blend better";
   - dampening

1. Make moist
   "The dew moistened the meadows";
   - wash [literary], dampen
    
2. Moisten with fine drops
   "moisten the meat with melted butter";
   - drizzle

Type of: splash, splosh [informal], sprinkle, wet, wetting