| 释义 |
ballast
ballast /ˈbæl.əst/ noun [U]
► F0 heavy matter such as sand or stone that is used at the bottom of a ship or a hot-air balloon to make it heavier, or the small stones on which railways and roads are madeThesaurus+: ↑Area, mass, weight and volume in generalThesaurus+: ↑Railways and railway linesThesaurus+: ↑Parts of ships and boats |