n any heavy material used to stabilize a ship or airship
n coarse gravel laid to form a bed for streets and railroads
n an attribute that tends to give stability in character and morals; something that steadies the mind or feelings
n a resistor inserted into a circuit to compensate for changes (as those arising from temperature fluctuations)
n an electrical device for starting and regulating fluorescent and discharge lamps
v make steady with a ballast
n. （保持船身稳定的）压舱物( ballast的名词复数 ); 镇定物; 安定; 压舱材料