The crossword solution for the term WHISTLE WETTER is SALIVA, which is a six-letter word. SALIVA is a watery substance produced in the mouths of humans and other animals. It is composed of water, electrolytes, mucus, and enzymes that help to break down food. SALIVA is important for keeping the mouth moist and aiding in digestion. When whistling, SALIVA is often used to wet the lips and tongue to produce a better sound.