- Nautical. any heavy material carried temporarily or permanently in a vessel to provide desired draft and stability.
- Aeronautics. 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 called ballast 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.
verb (used with object)
- to furnish with ballast: to ballast a ship.
- to give steadiness to; keep steady: parental responsibilities that ballast a person.
- in ballast, Nautical. carrying only ballast; carrying no cargo.
- any dense heavy material, such as lead or iron pigs, used to stabilize a vessel, esp one that is not carrying cargo
- crushed rock, broken stone, etc, used for the foundation of a road or railway track
- coarse aggregate of sandy gravel, used in making concrete
- anything that provides stability or weight
- electronics a device for maintaining the current in a circuit
- to give stability or weight to
“heavy material used to steady a ship,” 1520s, from Middle English bar “bare” (see bare; in this case “mere”) + last “a load, burden,” or borrowed from identical terms in North Sea Germanic and Scandinavian (cf. Old Danish barlast, 14c.). “Mere” because not carried for commercial purposes. Dutch balg-last “ballast,” literally “belly-load,” is a folk-etymology corruption.