Pronunciation: (hī'bôl"),[key] —n. 1. a drink of whiskey mixed with club soda or ginger ale and served with ice in a tall glass.
2. Railroads. a. a signal to start a train, given with the hand or with a lamp.
b. a signal for a train to move at full speed.
3. Mil. Slang.a hand salute.
—v.i. Slang.to move at full speed.
—v.t. to signal to (the engineer of a train) to proceed.