n. 压舱材料, 道碴材料

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.


Ballasting \Bal"last*ing\, n.
That which is used for steadying anything; ballast.