it's where your friend is so ignorant, everything that comes out of his mouth is like mush, and or "bullshit"
this is not cureable, it's also another term for (permafry, idiot, douchebag, etc..)
milkmouth- hey man.
milkmouth- so uh, uhm. uh, well. uh, yeah dude.
me- oh yes, you're definatly a milk mouth.