ballast
Heavy material that is placed in the hold of a ship (or in the gondola of a balloon), to provide stability.
Other meanings
Anything that steadies emotion or the mind.
Coarse gravel or similar material laid to form a bed for roads or railroads, or in making concrete; track ballast.
Word history
From Middle English "bar" (bare).
Where this comes from
This definition is adapted from “ballast” on Wiktionary, by its contributors, published under CC BY-SA 4.0. This page is published under the same licence.