from
The Collaborative International Dictionary of English v.0.48
Ballast \Bal"last\ (b[a^]l"last), n. [D. ballast; akin to Dan.
baglast, ballast, OSw. barlast, Sw. ballast. The first part
is perh. the same word as E. bare, adj.; the second is last a
burden, and hence the meaning a bare, or mere, load. See
{Bare}, a., and {Last} load.]
1. (Naut.) 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.
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2. Any heavy matter put into the car of a balloon to give it
steadiness.
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3. Gravel, broken stone, etc., laid in the bed of a railroad
to make it firm and solid.
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4. The larger solids, as broken stone or gravel, used in
making concrete.
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5. Fig.: That which gives, or helps to maintain, uprightness,
steadiness, and security.
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It [piety] is the right ballast of prosperity.
--Barrow.
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{Ballast engine}, a steam engine used in excavating and for
digging and raising stones and gravel for ballast.
{Ship in ballast}, a ship carrying only ballast.
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