bulkhead (n.)youdaoicibaDictYouDict[bulkhead 词源字典]
late 15c., with head (n.); the first element perhaps from bulk "framework projecting in the front of a shop" (1580s), which is perhaps from Old Norse bolkr "beam, balk" (see balk (n.)).[bulkhead etymology, bulkhead origin, 英语词源]