Ballasts

Part of speech: noun

Definitions

1. A heavy material used to provide stability and balance to a vessel or structure
2. A mechanical component that regulates the current in electrical equipment, particularly in lighting
3. A mass added to devices or vehicles to improve performance by lowering the center of gravity or ensuring proper weight distribution

Etymology: "Ballasts" is simply the plural of "ballast", so the history belongs to the singular. The base word is a compound of two Middle English elements: "bar", meaning "bare" in the sense of being empty or unloaded, and "last", meaning "load". Put together, the sense was roughly "a load carried to make a bare vessel or wagon usable." The idea is literal: a ship sailing without cargo would be unstable, so it needed weight stowed low in its hull. That original sense of weight for a vessel explains the modern meaning. The same principle, lowering the centre of gravity and balancing weight, is what the plural describes when it refers to added mass in machines or vehicles. The engineering use is a direct extension of the nautical one, not a separate coinage.

Synonyms: weights, counterbalances, stabilizers, supports, anchors