ballastとは 意味・読み方・使い方

語源

From Middle English bar (“bare”) + last (“load”).

発音

• (Received 発音, 米国発音) IPA^(key): /ˈbæl.əst/
• 韻: -æləst

名詞

ballast (usually uncountable, 複数形 ballasts)

1. (nautical) Heavy material that is placed in the hold of a ship (または in the gondola of a balloon), to provide stability.
2. (figuratively) Anything that steadies emotion or the mind.
3. Coarse gravel or similar material laid to form a bed for roads or railroads, or in making concrete; track ballast.
4. (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.
5. (countable, electricity, electronics) device used for stabilizing current in an electric circuit (e.g. in a tube lamp supply circuit)
6. (figurative) That which gives, or helps to maintain, uprightness, steadiness, and security.
   • 2018 June 17, Barney Ronay, “Mexico’s Hirving Lozano stuns world champions Germany for brilliant win”, in Katharine Viner, editor, The Guardian‎^[1], London: Guardian News & Media, →ISSN, →OCLC, archived from the original on 5 August 2019:

     With 73 minutes gone Rafael Márquez came on to add ballast at the back, appearing in his fifth World Cup aged 39 and with alleged links to drug trafficking, which he denies, on hold for now. And so they sat deep with a thin green line of five defenders ranged across their own penalty area as the game became a Mexican stand-off, attack versus defence.

   • a. 1677, Isaac Barrow, The Profitableness of Godliness

     It [piety] is the right ballast of prosperity.

派生語

動詞

ballast (三人称単数 現在形 ballasts, 現在分詞 ballasting, 過去形および過去分詞形 ballasted)

1. To stabilize or load a ship with ballast.
2. To lay ballast on the bed of a railroad track.
   • 1943 September and October, “Railway Construction and Operation at War Department Depots”, in Railway Magazine, page 262:

     The task of a Railway Construction Company, R.E., is to lay and ballast the track; [...].

   • 1948 September and October, W. S. Darby, “The Gold Coast Railway—1”, in Railway Magazine, page 287:

     Although the track is ballasted, it does not prevent clouds of reddish dust from the laterite soil blowing about when the train is in motion; after a journey with the windows open a bath is a necessity!

3. To weigh down with a ballast.
   • 1938, Norman Lindsay, Age of Consent, 1st Australian edition, Sydney, N.S.W.: Ure Smith, published 1962, →OCLC, page 35:

     The noosance was […] that to make the umbrella effective he would have to carry abroad such weight to ballast it as would put the whole contraption out of action for carrying abroad at all.

派生語

• reballast, reballasting

Gallery

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  Ballast provides a supporting bed for rail tracks

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  Several typical styles of magnetic ballasts for fluorescent lamps