Synonymous with the word drunk, it is used in it's place as drunk people tend to be belligerent and not only are lippy, they even generally spittle a little more as they talk.
Ethnic guy: The sluts calling us over
Aussie bloke: How random why?
Ethnic guy: I don’t know cuz
Aussie bloke: Spitty or what mate
Ethnic guy: Fucken oath cuz let’s go
The sensation one feels when their mouth begins to salivate and fill with spit, after having had too much to drink. This is then usually followed by vomiting, however some can fight it off. Either way, you'll be spittin'.