alderman
/ˈɔ:ldəmən; `ɔldɚmən/ n
(pl -men / -mən;-mən/)
1 (Brit) (esp formerly) member of a county or borough council, next in rank below the mayor （尤指旧时地位仅次於市长的）高级市政官.
2 (US) (in some cities) member of the city council, representing a particular part of the city （某些城市中的）市参议员.