Noun
1. any heavy material used to stabilize a ship or airship
2. coarse gravel laid to form a bed for streets and railroads
3. an attribute that tends to give stability in character and morals; something that steadies the mind or feelings
4. a resistor inserted into a circuit to compensate for changes (as those arising from temperature fluctuations)
5. an electrical device for starting and regulating fluorescent and discharge lamps