Ballastic

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 alt-tude and, less often, of att-tude, 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.
electricity.

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.

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.
noun
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
co-rs- aggregate of sandy gravel, used in making concrete
anything that provides stability or weight
(electronics) a device for maintaining the current in a circuit
verb (transitive)
to give stability or weight to
n.

“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.