ETYM Dutch ballast; akin to Dan. baglast, ballast, OSw. barlast, Swed. ballast. The first part is perh. the same word as Eng.
1. Weighted material carefully placed toward the bottom of a craft's hull to stabilize a ship or airship.
2. Crushed gravel placed under railroad tracks.
3. (Casual) Dense, hearty food.
An electrical device used in fluorescent and HID fixtures. It furnishes the necessary starting and operating characteristics to the lamp for proper performance.

To make steady with a ballast.

An electrical device used in fluorescent and hid fixtures. It furnishes the necessary starting and operating characteristics to the lamp for proper performance.