Other forms: ballasts
Ballast is heavy material carried to keep something steady. The grey crushed stone packed under railway sleepers is ballast, and so are the sandbags a balloon crew tip out to climb.
A ship with no cargo rides too high and rolls, so it takes on stone or seawater as ballast — sailing in ballast means sailing empty but weighted. The railway sense is the one you see every day: sharp granite chips that hold the sleepers in place, spread the load and let the rain drain away. Figuratively, ballast is whatever steadies a person or a plan, as in her sister was the ballast in that family. In lighting, a ballast is the small device that limits the current through a fluorescent tube — the same idea in another trade. As a verb, you ballast a hull or a track.
1nounballastHeavy material carried in a ship, balloon or vehicle to keep it stable.~70%
“They pumped seawater into the tanks as ballast for the crossing.”
2nounrailThe bed of crushed stone that railway sleepers are laid in.~26%
“A tamping machine packed fresh ballast under the sleepers.”
3noungivesSomething that gives steadiness to a person, an argument or an institution.~2%
“Her years on the shop floor gave the board some ballast.”
4noundeviceThe device that controls the current through a fluorescent or discharge lamp.~2%
“The strip light buzzed until the electrician replaced the ballast.”
Shares are an estimate: a language model read 11 sentences found in the wild and placed 11 of them on a sense — a count of our sample, not a measurement of English.
Ballast comes from Middle English, built from bar, 'bare', and last, 'load' — a bare load. That is what it still is: cargo that earns nothing, carried only so the ship stands up straight.
Middle English
bar — bare
English, today
ballast
Built from
From Middle English bar (“bare”) + last (“load”).
Etymology from Wiktionary, CC BY-SA