The inability to speak properly because of the genormityness of the person’s lips. Usually referring to African Americans with abnormally large lips and who sound like they are trying to speak with a mouth full of marshmallows.

Got the covid-19 vaccine

a term used to describe a state of intoxication in which the individual cannot speak properly or when the intoxicated individual makes random remarks having nothing to do with the preceding conversation.

After 15 or more beers you are unable to form letters into words and words into sentences. it just comes out as mush

Mush mouth is a particularly interesting oral sex technique involving crackers (typically saltines but anything dry will work). It is performed by chewing up enough crackers to render one incapable of speaking clearly, receiving a load in the mouth, mixing it all together, then slowly pushing it out of the mouth to run all over the face and make a gunky mess.

Usenet (rec.arts.poems) /term of endearment/ for the poet Rob, who in his live performances whistle lisps his poems through a mouthful of gunk.