aldermanyoudaoicibaDictYouDict[alderman 词源字典]
alderman: [OE] Alderman preserves the notion that those who are old (the ‘elders’) are automatically in charge. In Anglo-Saxon England the ealdor was the chief of a family or clan, by virtue of seniority (the word is based on the adjective eald ‘old’). Alderman (Old English ealdorman) was a political title or rank adopted probably in the early 8th century for someone who exercised in society at large an authority equivalent to that of the ealdor.

In effect, this meant that an alderman acted as a sort of viceroy to the king in a particular district. In the 12th century the title became applied to the governor of a guild, and as the guilds gradually took over some functions of local government, an alderman became a senior councillor. The title was officially abolished in Britain in 1974.
=> old[alderman etymology, alderman origin, 英语词源]
alderman (n.)youdaoicibaDictYouDict
Old English aldormonn (Mercian), ealdormann (West Saxon) "ruler, prince, chief; chief officer of a shire," from aldor, ealder "patriarch" (comparative of ald "old;" see old) + monn, mann "man" (see man (n.)). A relic of the days when the elders were automatically in charge of the clan or tribe, but already in Old English used for king's viceroys, regardless of age. The word yielded in Old English to eorl, and after the Norman Conquest to count (n.). Meaning "headman of a guild" (early 12c.) passed to "magistrate of a city" (c. 1200) as the guilds became identified with municipal government.