bulwarkyoudaoicibaDictYouDict[bulwark 词源字典]
bulwark: [15] Bulwark comes from Middle High German bolwerc ‘fortification’, a compound formed from bole ‘plank’ (the same word as English bole ‘tree trunk’) and werc, equivalent to English work. It thus originally meant ‘rampart constructed out of planks or tree trunks’. The word was shared by other Germanic languages, including Swedish bolverk, and French borrowed it as boullewerc, which has since become boulevard.
=> bole, boulevard, work[bulwark etymology, bulwark origin, 英语词源]
bulwark (n.)youdaoicibaDictYouDict
"planking or woodwork round the uppermost parts of a vessel," early 15c., from Middle Dutch bulwerke or Middle High German bolwerc, probably from bole "plank, tree trunk" (from Proto-Germanic *bul-, from PIE root *bhel- (2) "to blow, swell;" see bole) + werc "work" (see work (n.)). Figurative sense "means of defense or security" is from 1570s.