If an animal slavers, liquid comes from its mouth, for example because it is about to attack and eat something. Mad guard dogs slavered at the end of their chains. the wolf's slavering jaws. = slobber. to let saliva (=liquid produced inside your mouth) come out of your mouth, especially because you are hungry = drool (From a language)
[ 'sla-v&r, 'slA-, 'slä ] (verb.) 14th century. Middle English, of Scandinavian origin; akin to Old Norse slafra to slaver; akin to Middle Dutch slabben to slaver.