Source : Webster's Revised Unabridged Dictionary (1913)
Alderman \Al"der*man\ ([add]l"d[~e]r*man), n.; pl. {Aldermen}.
[AS. aldormon, ealdorman; ealdor an elder + man. See {Elder},
n.]
1. A senior or superior; a person of rank or dignity. [Obs.]
Note: The title was applied, among the Anglo-Saxons, to
princes, dukes, earls, senators, and presiding
magistrates; also to archbishops and bishops, implying
superior wisdom or authority. Thus Ethelstan, duke of
the East-Anglians, was called Alderman of all England;
and there were aldermen of cities, counties, and
castles, who had jurisdiction within their respective
districts.
3. One of a board or body of municipal officers next in order
to the mayor and having a legislative function. They may,
in some cases, individually exercise some magisterial and
administrative functions.
Source : WordNet®
alderman
n : a member of a municipal legislative body (as a city
council); "aldermen usually represent city wards"