Meaning

noun saliva spilling from the mouth

verb let saliva drivel from the mouth

originFrom Middle English sloberen, borrowed from Middle Dutch slobberen (> Modern Dutch slobberen (“to slobber”)), related to West Frisian slobberje (“to slurp”), German Low German slubbern (“to slobber”). Doublet of slabber and slaver. Compare also German schlabbern (“to slobber”). At least in the sense of "saliva", apparently not related to English slob, from Irish slaba (“mud”).

Etymology from Wiktionary, CC BY-SA 3.0