ballast
英 ['bæləst]
美['bæləst]
	    - n. 压舱物,[建] 压载物;道渣,碎石
 - vt. 给…装压舱物;给…铺道渣
 
英英释意
- 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