caisson (n.)youdaoicibaDictYouDict[caisson 词源字典]
1704, from French caisson "ammunition wagon, box, crate," from Middle French caisson "large box" (16c.), from Italian cassone, augmentative form of cassa "a chest," from Latin capsa "a box" (see case (n.2)).[caisson etymology, caisson origin, 英语词源]