1 : a heavy substance (such as rocks or water) 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) tossed several tons of ballast overboard.What is a synonym for ballast?
Ballast is any substance that is used in ships or hot-air balloons to make them heavier and more stable. Ballast usually consists of water, sand, or iron. Synonyms: counterbalance, balance, weight, stability More Synonyms of ballast.What is the ballast on a car?
Ballast is material that is used to provide stability to a vehicle or structure. Ballast, other than cargo, may be placed in a vehicle, often a ship or the gondola of a balloon or airship, to provide stability.