Saliva is the liquid your mouth makes by itself. It keeps the mouth wet, helps you taste, and helps you swallow; it even starts to break food down a little. Doctors and science books say saliva. At home, people more often say spit, or just the water in your mouth. Though actually, spit can also mean the act of sending that liquid out, which saliva does not: saliva is the liquid itself. Animals have saliva too. When your mouth waters at food, that is more saliva arriving. The everyday verb is salivate, not “to saliva.”