from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Heavy material that is placed in the hold of a ship or the gondola of a balloon to enhance stability.
- n. Coarse gravel or crushed rock laid to form a bed for roads or railroads.
- n. The gravel ingredient of concrete.
- n. Something that gives stability, especially in character.
- transitive v. To stabilize or provide with ballast.
- transitive v. To fill (a railroad bed) with or as if with ballast.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. Heavy material that is placed in the hold of a ship (or in the gondola of a balloon), to provide stability.
- n. Anything that steadies emotion or the mind.
- n. Coarse gravel or similar material laid to form a bed for roads or railroads.
- n. 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.
- n. device used for stabilizing current in an electric circuit (e.g.in a tube lamp supply circuit)
- v. To stabilize or load a ship with ballast.
- v. To lay ballast on the bed of a railroad track.
from the GNU version of the Collaborative International Dictionary of English
- n. Any heavy substance, as stone, iron, etc., put into the hold to sink a vessel in the water to such a depth as to prevent capsizing.
- n. Any heavy matter put into the car of a balloon to give it steadiness.
- n. Gravel, broken stone, etc., laid in the bed of a railroad to make it firm and solid.
- n. The larger solids, as broken stone or gravel, used in making concrete.
- n. Fig.: That which gives, or helps to maintain, uprightness, steadiness, and security.
- transitive v. To steady, as a vessel, by putting heavy substances in the hold.
- transitive v. To fill in, as the bed of a railroad, with gravel, stone, etc., in order to make it firm and solid.
- transitive v. To keep steady; to steady, morally.
from The Century Dictionary and Cyclopedia
- n. Weight carried by a ship or boat for the purpose of insuring the proper stability, both to avoid risk of capsizing and to secure the greatest effectiveness of the propelling power.
- n. Bags of sand placed in the car of a balloon to steady it and to enable the aëronaut to lighten the balloon, when necessary to effect a rise, by throwing part of the sand out.
- n. Gravel, broken stones, slag, or similar material (usually called road-metal), placed between the sleepers or ties of a railroad, to prevent them from shifting, and generally to give solidity to the road.
- n. Figuratively, that which gives stability or steadiness, mental, moral, or political.
- To place ballast in or on; furnish with ballast: as, to ballast a ship; to ballast a balloon; to ballast the bed of a railroad. See the noun.
- Figuratively: To give steadiness to; keep steady.
- To serve as a counterpoise to; keep down by counteraction.
- To load; freight.
- To load or weigh down.
- n. The rough masonry of the interior of a wall, or that laid upon the vault; masonry used where weight and solidity are needed. Compare filling, 7, and back-filling.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. any heavy material used to stabilize a ship or airship
- n. an attribute that tends to give stability in character and morals; something that steadies the mind or feelings
- n. a resistor inserted into a circuit to compensate for changes (as those arising from temperature fluctuations)
- n. an electrical device for starting and regulating fluorescent and discharge lamps
- v. make steady with a ballast
- n. coarse gravel laid to form a bed for streets and railroads
Perhaps from Old Swedish or Old Danish barlast : bar, mere, bare; see bhoso- in Indo-European roots + last, load.(American Heritage® Dictionary of the English Language, Fourth Edition)
From Middle Low German, from Old Norse (bar, "bare") + (last, "load") (Wiktionary)