- a ball that is batted up into the air.
Compare ground ball.
Origin of fly ball
An Americanism dating back to 1860–65
Also called fly.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for fly ball
The fly-ball governor replaced the throttle-valve which was at first used by Watt to regulate the speed of his engines.The Story of Great Inventions
Elmer Ellsworth Burns
Engines of the slide-valve type are usually provided either with a fly-ball throttling governor, or a shaft governor.Steam Engines