In old slang, milkshake mean butt.
If you mean slang as in internet slang, then it means "Certified Old Fart".
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.
Limberlost is old slang for a dense, untamed forest or wilderness area. It was used in the early 20th century to refer to a place that was difficult to navigate or explore due to its dense vegetation.
Slang oud are 2 words in Afrikaans, with slang referring to a snake and oud referring to old.
To be Asian or to be a coward, slang from the old west.
OG in slang stands for "old gangsta." Ex. My father thinks he's a OG.
This is an old slang word for teacher
Awful blob is old slang and if you don't believe me then check the Internet and type is awful blob old slang or modern slang? And in seconds you will see that I am right about old blob being old slang
OMGB stands for Old Man Gang Bang.
Calling someone a 'tomato' is often a playful or affectionate way to describe them as looking red or blushing, usually due to embarrassment or shyness. It can also sometimes refer to someone having a round and plump appearance.
Old sailing slang meaning to be no longer in danger.
Old time expression for a big hit, a success.