"Plug is dry" is slang for when a drug dealer is temporarily out of supply. It means that the dealer doesn't have any drugs available for sale at the moment.
In slang, "plug" typically refers to a person who can supply you with illegal or black market goods, particularly drugs. It can also be used more broadly to refer to anyone who can hook you up with something you need.
If you mean slang as in internet slang, then it means "Certified Old Fart".
Slang is slang It's the s' "LANG " uage.
In old slang, milkshake mean butt.
Dough is a slang word for money.
he means what does being a sponge mean in slang
It is slang for having sex.
Cool itself, unless you are using it to mean mildly cold, is a slang word. Just because it is old slang doesn't mean that it is not still slang.
BTM is a slang acronym for "Be There Moment."
Tat is also slang for tattoo
That is not slang, it is a clear plastic sheet.