a condition in which the flow of saliva is reduced and there is not enough saliva to keep the mouth moist. Dry mouth can be the result of certain medications (such as antihistamines and decongestants), certain diseases (such as Sjögren's syndrome, HIV/AIDS, Alzheimer's disease, diabetes), certain medical treatments (such as head and neck radiation), as well as nerve damage, dehydration, tobacco use, and surgical removal of the salivary glands.
The condition of not having enough saliva to keep the mouth wet. This is due to inadequate function of the salivary glands. Everyone has dry mouth once in a while when they are nervous, upset or under stress. But if someone has a dry mouth most all of the time, it can be uncomfortable and lead to serious health problems. See the entire definition of Dry mouth