D defs.my
Entry 2 senses Webster, 1913

highball

/(hī"ba̤l`)/ · high·ball · IPA
01 n. An alcoholic beverage having a liquor such as whiskey mixed with water or a carbonated beverage, and usually served with ice in a tall glass.
  1. 1.
    An alcoholic beverage having a liquor such as whiskey mixed with water or a carbonated beverage, and usually served with ice in a tall glass.
  2. 2.
    A railroad track signal permitting the engineer to proceed at full speed.(Railroads)