Drooling is when we open our mouths a little too wide and saliva begins to spill out in small quantities. We are trying to make sure that this does not happen so that we do not embarrass ourselves since appearances and honor are some things that we care a great deal for.
If you have a dream where you are drooling then this probably means that you are drooling in real life. Sometimes the drool from your mouth can actually be felt by the outside of your mouth so that you know that you are drooling in real life when you are dreaming. It is your mind's clever way of letting you know that it is time for you to close your mouth. Having your mouth open puts you at a disadvantage when you sleep because it makes your throat dry which will cause you to wake up earlier than you had hoped and it also gets things messy and smelly. You are going to have a yellow spot on your pillow if you let your slobber escape through your pillow case and onto your pillow. Try to let yourself wake up if you have a dream about drooling to prevent something like this from happening at an inopportune time.
Sometimes this kind of dream really does have its own meaning though and doesn't have to do with the fact that you might be drooling on the outside. If this is the case then this means that you are dreaming of drooling because you feel like you are letting too many secrets out lately. This is not because you are doing it purposefully. You are just letting it slip and it is not a good or healthy thing for you to do.