ballast

Definitions

• (nautical) Heavy material that is placed in the hold of a ship (or in the gondola of a balloon), to provide stability.
• (figuratively) 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.
• (construction) A material, such as aggregate or precast concrete pavers, which employs its mass and the force of gravity to hold single-ply roof membranes in place.
• (countable) device used for stabilizing current in an electric circuit (e.g. in a tube lamp supply circuit)
• (figurative) That which gives, or helps to maintain, uprightness, steadiness, and security.