ballast

BAL'LAST, n.

1. Heavy matter, as stone, sand or iron, laid on the bottom of a ship or other vessel, to sink it in the water, to such a depth, as to enable it to carry sufficient sail, without oversetting.

Shingle ballast is ballast of coarse gravel.

2. Figuratively, that which is used to make a thing steady.

BAL'LAST, v.t. To place heavy substances on the bottom of a ship or vessel, to keep it from oversetting.

2. To keep any thing steady, by counterbalancing its force.