- liquor, usually whiskey or brandy, mixed with water, soda water, ginger ale, etc. and served with ice in a tall glass
- a railroad signal, originally a ball hung above the tracks, meaning “go ahead”: sometimes used fig.
Origin of highballhighballsense from uncertain or unknown; perhaps high + ball, bartender's slang for “whiskey glass”: influenced, influence uncertain or unknown; perhaps by the verb
Origin of highball< highballnoun