Толковый словарь английского языка - ballast

I. noun see: lade Date: 1530 a heavy substance placed in such a way as to improve stability and control (as of the draft of a ship or the buoyancy of a balloon or submarine), something that gives stability (as in character or conduct), gravel or broken stone laid in a railroad bed or used in making concrete, a device used to provide the starting voltage or to stabilize the current in a circuit (as of a fluorescent lamp), II. transitive verb Date: 1538 to steady or equip with or as if with ~, to fill in (as a railroad bed) with ~