Ballast

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. [1913 Webster]

2. Any heavy matter put into the car of a balloon to give it steadiness. [1913 Webster]

3. Gravel, broken stone, etc., laid in the bed of a railroad to make it firm and solid. [1913 Webster]

4. The larger solids, as broken stone or gravel, used in making concrete. [1913 Webster]

5. Fig.: That which gives, or helps to maintain, uprightness, steadiness, and security. [1913 Webster]

It [piety] is the right ballast of prosperity. --Barrow. [1913 Webster]

{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. [1913 Webster]