Bal"last (băl"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.
2. Any heavy matter put into the car of a balloon
to give it steadiness.
3. Gravel, broken stone, etc., laid in the bed of a
railroad to make it firm and solid.
4. The larger solids, as broken stone or gravel,
used in making concrete.
5. Fig.: That which gives, or helps to maintain,
uprightness, steadiness, and security.
It [piety] is the right ballast of prosperity.
Barrow.
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.
Bal"last, v. t. [imp. & p.
p. Ballasted; p. pr. & vb. n.
Ballasting.] 1. To steady, as a vessel, by
putting heavy substances in the hold.
2. To fill in, as the bed of a railroad, with
gravel, stone, etc., in order to make it firm and solid.
3. To keep steady; to steady, morally.
'T is charity must ballast the heart.
Hammond.
