"Highball" is name of a variety of cocktails that include a shot of a spirit spirit (usually, but not always, whiskey) and large amount of a non-alcoholic mix and served over ice a tall glass. Scotch and soda, rum and coke, seven-and-seven.
Highball may also refer to a type of glass, or a specific mixed drink called the "whiskey highball" (which is a shot of whiskey topped with ginger ale, over ice)
My daughters refer to hobos all the time when they're harassing me. When they were growing up I'd tell them to change their clothes because they looked like a hobo.
As far as something not really heard anymore, whoopsie daisy/oopsie daisy.
When I was a kid I wore "culottes." I don't ever see that word anymore. Culottes are like capri pants but with a huge flare/flowy material so they looked like a skirt, but actually had separate legs. They hit below the knee but higher than the ankle kind of like what capris are now.