Sialorrhea
Sialorrhea is a condition characterized by the secretion of drool in the resting state. It is often the result of open-mouth posture from CNS depressants or sleeping on one's side. In the resting state, saliva may not build at the back of the throat, triggering the normal swallow reflex, thus allowing for the condition. Moreover, neurodegenerative diseases, congenital defects, or physical obstructions like stenosis or tumors of the upper aerodigestive tract can be the reason for excessive drooling states.
It may be more common when resting soon after meals.
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