Xerostomia, dryness of the mouth; a medical condition commonly known as "cotton mouth". Often, cotton mouth is accompanied by its cousin, known as “the munchies.”
This term describes having an extremely dry mouth from smoking or orally consuming cannabis, and can ultimately result in dehydration. For long time users of marijuana, cotton mouth creates a decline in taste buds and poor oral hygiene. Cotton mouth can be avoided by remembering to drink water as you smoke, but it is sometimes hard to remember anything as you smoke... so it's still a common occurrence.