ballast: Meaning and Definition of
Pronunciation: (bal'ust), [key]
- any heavy material carried temporarily or permanently in a vessel to provide desired draft and stability.
- something heavy, as bags of sand, placed in the car of a balloon for control of altitude and, less often, of attitude, or placed in an aircraft to control the position of the center of gravity.
- anything that gives mental, moral, or political stability or steadiness: the ballast of a steady income.
- gravel, broken stone, slag, etc., placed between and under the ties of a railroad to give stability, provide drainage, and distribute loads.
- Also calledballast resistor.a device, often a resistor, that maintains the current in a circuit at a constant value by varying its resistance in order to counteract changes in voltage.
- a device that maintains the current through a fluorescent or mercury lamp at the desired constant value, sometimes also providing the necessary starting voltage and current.
- carrying only ballast; carrying no cargo.
- to furnish with ballast: to ballast a ship.
- to give steadiness to; keep steady: parental responsibilities that ballast a person.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.