ballast (Noun) — Any heavy material used to stabilize a ship or airship.
ballast (Noun) — Coarse gravel laid to form a bed for streets and railroads.
ballast (Noun) — An attribute that tends to give stability in character and morals; something that steadies the mind or feelings.
ballast (Noun) — A resistor inserted into a circuit to compensate for changes (as those arising from temperature fluctuations).
ballast (Noun) — An electrical device for starting and regulating fluorescent and discharge lamps.
ballast (Verb) — Make steady with a ballast.