boroughyoudaoicibaDictYouDict[borough 词源字典]
borough: [OE] Borough (Old English burg or burh) comes from Germanic *burgs ‘fortress’ (whence also German burg ‘castle, stronghold’). It was a derivative of the base *burg- ‘protect’ (whence also bury), a variant of *berg- (source of English barrow ‘mound’ and German berg ‘mountain’) and *borg- (source of English borrow).

At some time during the prehistoric Germanic period a progression in meaning began to take place from ‘fortress’ (which had largely died out in English by 1000), through ‘fortified town’, to simply ‘town’. Romance languages borrowed the word, giving for instance French bourg, from which English gets burgess [13] and bourgeois [16]. Burrow [13] is probably a variant form.
=> bourgeois, burgess, burrow, bury[borough etymology, borough origin, 英语词源]
borough (n.)youdaoicibaDictYouDict
Old English burg, burh "a dwelling or dwellings within a fortified enclosure," from Proto-Germanic *burgs "hill fort, fortress" (cognates: Old Frisian burg "castle," Old Norse borg "wall, castle," Old High German burg, buruc "fortified place, citadel," German Burg "castle," Gothic baurgs "city"), from PIE root *bhergh- (2) "high," with derivatives referring to hills, hill forts, fortified elevations (source also of Old English beorg "hill;" see barrow (n.2)).

In German and Old Norse, chiefly as "fortress, castle;" in Gothic, "town, civic community." Meaning shifted in Middle English from "fortress," to "fortified town," to simply "town" (especially one possessing municipal organization or sending representatives to Parliament). In U.S. (originally Pennsylvania, 1718) often an incorporated town; in Alaska, however, it is the equivalent of a county. The Scottish form is burgh. The Old English dative singular byrig survives in many place names as -bury.