noun any heavy material used to stabilize a ship or airship.
noun coarse gravel laid to form a bed for streets and railroads.
noun an attribute that tends to give stability in character and morals.
noun a resistor inserted into a circuit to compensate for changes (as those arising from temperature fluctuations).
— synonyms: ballast_resistor, barretter
noun an electrical device for starting and regulating fluorescent and discharge lamps.
— synonyms: light_ballast