Moisture in the Mouth, Spit
Puzzle 13 of Countdown to 2020 Piece of Cake Pack
Question is: Moisture in the Mouth, Spit
and the answer is: SALIVA
Word Meaning:
SALIVA — (physiology) A clear, slightly alkaline liquid secreted into the mouth by the salivary glands and mucous glands, consisting of water, mucin, protein, and enzymes. It moistens the mouth, lubricates ingested food, and begins the breakdown of starches.
Definitions from Wiktionary.