Real Dictionary

saliva in American English
the thin, watery, slightly viscid fluid secreted by the salivary glands: it serves as an aid to swallowing and digestion by moistening and softening food, and contains enzymes which convert starch to dextrin and maltose
noun: a viscid, watery fluid, secreted into the mouth by the salivary glands, that functions in the tasting, chewing, and swallowing of food, moistens the mouth, and starts the digestion of starches

saliva in British English
noun: the secretion of salivary glands, consisting of a clear usually slightly acid aqueous fluid of variable composition. It moistens the oral cavity, prepares food for swallowing, and initiates the process of digestion